CN1710126A

CN1710126A - Ecological environmental-protection lead-free free-cutting low antimony bismuth brass alloy and its manufacturing method

Info

Publication number: CN1710126A
Application number: CN 200510050425
Authority: CN
Inventors: 张明; 谢潇; 蔡洎华; 孟宪旗
Original assignee: BOWEI GROUP Co Ltd NINGBO
Current assignee: Ningbo Powerway Alloy Material Co Ltd
Priority date: 2005-06-24
Filing date: 2005-06-24
Publication date: 2005-12-21
Anticipated expiration: 2025-06-24
Also published as: WO2006136065A1; CN1329539C

Abstract

The invention discloses environmental non-lead easy cutting low Sb-Bi brass alloy and its production technique. The material is made up of copper of 55 to 65 weight percent, Bi: 0.3 to 1.5, Sb: 0.05 to 1.0, boracium: 0.0002 to 0.5 weight percent, other elements: 0.2 to 1.2 weight percent which includes at least two of following elements; titanium, nickel, iron, stannum, phosphor. Others elements are zinc and inevitable extraneous elements in which lead content is lesser than 0.1 weight percent. Its production technique is alloying and cover protecting to refining the low Di Bi copper alloy during which the boracium and Di fast solidify into metal inter compound uniformly arranging the metal Bi at intracrystalline and crystal boundary, and continuously casting the material into brass blocks, press the blocks at great pressing ratio at 680 to 760 deg.C, intermediate heat process follows the cold processing condition at 500 to 700 deg.C, finally anneal under 400 deg.C to eliminate the stress. The product alloy has got fine cutting, anti-detin and anti stress crack performance, and is very adapted as components shaping by removal. It is of low cost, and totally meets the international environment, health care standards.

Description

Ecological, environmental protective new type leadless easy cutting low antimony bismuth brass alloys and manufacture method thereof

Technical field

The present invention relates to a kind of lead-free brass alloys, relate in particular to a kind of lead-free free-cutting low antimony bismuth brass alloy (PWEHSCBRASS) with excellent cutting ability, mechanical property and corrosion resistance nature.It is specially adapted to the connector of electronics, telecommunication apparatus, computer; Home electric; The optoelectronic components of light fixture and photographic apparatus; Component in toy for children and machinery and the automobile industry; Fields such as waterworks pipeline foundry goods, valve member, the manufacturing of switch web member.It is a kind of new metallic material that helps human health and environment protection, also is the meeting of present widespread use causes the leaded brass of baneful influence to human body and environment another new type ideal substitute.

Background technology

Leaded brass has characteristics such as good cold and hot working performance, fabulous cutting ability and self-lubricating, can satisfy the machining of different shape component, so Winn bronze is also just by the wide spectrums such as component manufacturing of optoelectronic components, automobile and the machinery manufacturing industry of universally acknowledged component, light fixture and the photographic apparatus that is widely applied to the pipeline foundry goods of electronics, telecommunication, computer part, domestic water supply system and accessory, household electrical appliances and toy for children for important base mateiral.

Yet lead is a kind of to environment and harmful element, plumbous particularly can cause irreversible damage to children's kidney and cranial nerve to blood of human body and neural system, and serious meeting causes that blood lead, brain lead poisoning, nerve are obstructed, backwardness.The medical expert of countries in the world has found that Winn bronze has constituted threat to human health and environmental health in recent years, medical research institutes such as Northern Europe, the U.S., Japan and China have all made the report that leaded brass works the mischief to human environment, in February, 2004, the children of World Health Organization cooperation center was carried out the lead poisoning investigation in 15 cities of China to 1.7 ten thousand children, wherein toy for children is listed in one of Hazard Factor that cause children ' s lead poisoning, thereby the government that national governments have also put into effect in succession to the copper alloy containing lead application orders within a certain time.Chinese Government has also put into effect in succession in the recent period with the world and has ordered the corresponding to mandatory rules of laws such as " electronics and IT products prevention and cure of pollution management methods " within a certain time.

In view of the foregoing, in recent years particularly since 2003, the U.S., the European Community, Japan, countries such as China have made ordering within a certain time of strict control respectively to the lead content in the copper alloy (wherein the content of electronics and IT products lead must less than 0.1%) with in the leaching amount of Pb in Drinking Water, and will constantly reduce wherein lead content, thereby the application of Winn bronze will face strict restriction and challenge, therefore developing Lead free cutting copper alloys in succession substitutes copper alloy containing lead, be the instant key subjects that world today's metallic substance production is faced, also be the international EHS of enforcement plan (E: environmental protection, H: health, S: world's recycling economy safety) the key subjects that must solve.

External at present as the U.S., lead-free brass alloys have also been invented by Germany and Japan, wherein for example disclosed in Chinese patent application number 02121991.5 specification sheets " leadless free-cutting brass alloy material and its manufacture method ", it is the leadless free-cutting brass alloy material of Japanese Mikoshi Metal Co., Ltd. invention, its composition and manufacture method are respectively: this alloy contains weight %: copper: 60.0～62.0%, bismuth: 0.5～2.2%, aluminium: 0.01～0.1%, tin: 0.5～1.6%, phosphorus: 0.04～0.15%, all the other are zinc and unavoidable impurities composition, under 460～600 ℃ of temperature, carry out thermal treatment in 30 minutes～4 hours, with the speed of cooling slow cooling below 70 ℃/hour.Another invention be the number of patent application of German Wieland company research and development be 200410004293 " Pb-free copper-alloy and its application 〉, this alloy is made up of following ingredients: copper: 70.0～83.0%, silicon: 1～5%, tin: 0.01～2%, iron: 0.01～0.3% and/or cobalt: 0.01～0.3%, nickel: 0.01～0.3%, manganese: 0.01～0.3%, and surplus is zinc and unavoidable impurities.

Summary of the invention

The objective of the invention is for a kind of lead-free have excellent in machinability, cold and hot formability and good weldability and good mechanical property are provided, has simultaneously excellent corrosion resisting property again, and alternative copper alloy containing lead and can not cause environmental pollution and help the new type leadless easy cutting low antimony bismuth brass alloys of human health, be different from external bismuth yellow brass alloy and manufacture method thereof simultaneously again.

The objective of the invention is by providing lead-free free-cutting low antimony bismuth brass alloy to realize with following each row alloy composition:

The alloy composition of one of lead-free free-cutting low antimony bismuth brass alloy of the present invention is: copper: 55～65wt%, bismuth: 0.3～1.5wt%, antimony: 0.05～1.0wt%, boron: 0.0002～0.05wt%, other element: 0.2～1.2wt%, described other element is at least two kinds of elements that are selected from titanium, nickel, iron, tin, phosphorus, the rare earth metal, all the other are zinc and unavoidable impurities, and content plumbous in the unavoidable impurities is less than 0.1wt%; The copper zincification adds bismuth and adds antimony and add boron greater than 97wt% in the described alloy composition, and wherein zinc greater than 35.5wt%.

The preferable of one of described lead-free free-cutting low antimony bismuth brass alloy consists of: copper: 58～63wt%, bismuth: 0.4～1.4wt%, antimony: 0.06～0.8wt%, boron: 0.0006～0.03wt%, other element: 0.2～1.0wt%, described other element is at least two kinds of elements that are selected from titanium, nickel, iron, tin, phosphorus, the rare earth metal, all the other are zinc and unavoidable impurities, and content plumbous in the unavoidable impurities is less than 0.1wt%; The copper zincification adds bismuth and adds antimony and add boron greater than 97.5wt% and be not more than 99.8wt% in the described alloy composition, and wherein zinc is greater than 35.5wt%.

The phase composite of one of described lead-free free-cutting low antimony bismuth brass alloy is: based on α, β two-phase, the bismuth that is uniformly distributed in intracrystalline and crystal boundary with free state mutually, a small amount of tiny hard crisp phase that contains compound between antimony metal that is uniformly distributed in the solid solution attitude of crystal boundary.

One of described lead-free free-cutting low antimony bismuth brass alloy is to utilize bismuth and antimony to substitute lead, based on bismuth, further improves the cutting ability of alloy with the auxiliary bismuth of antimony; Based on boron, improve the anti dezincification character energy of alloy with auxiliary boron such as antimony, tin simultaneously.

The adding of bismuth can improve the machinability of alloy.The solid solubility of bismuth in copper is extremely low, even the solubleness in the time of 800 ℃ also only 0.01%, but the solubleness in the liquation is very big, bismuth precipitates in process of setting, form the second phase particle of disperse, the disperse phase fusing point of this bismuth lower (271.3 ℃), in the contact surface local heating of cutter head and bits and instant melting, this fuse effect helps to change the shape and the lubricated cutter of smear metal, make alloy in machining, easily form short chip breaking point thereby play, bonding between minimizing cutter head and the workpiece and seam and the effect that improves cutting speed, and then make alloy have satisfied cutting ability.But bi content was greater than 1.5% o'clock, can cause the brittle failure increase, our employing is that advocating peace with the antimony that adds easy formation sosoloid is the alloying scheme of assisting with the bismuth that adds low levels for this reason, make the stibiated metallic compound of easy cutting chip breaking (nontoxic with solid solution, healthy form is present in the alloy) embrittlement mutually also accumulates near the crystal boundary, make this alloy obtain more excellent cutting ability and other over-all properties, thereby reached based on bismuth, assist bismuth further to improve the purpose of the cutting ability of alloy with antimony, this alloy has been obtained as the excellent cutting ability of leaded brass.Add simultaneously some crystal grain thinnings again, suppress dezincify and control other element of trace that the alloy brittle failure is inclined to, and then make that stibiated metallic compound is more tiny to be evenly distributed on the crystal boundary, and make bismuth metal be uniformly distributed in intracrystalline and crystal boundary, make alloy in machining, easily form short chip breaking point, increased over-all propertieies such as the cutting ability of alloy and anti-corrosion anti dezincification character effectively, thereby made the low antimony bismuth brass alloys obtain to resemble cutting ability excellent the leaded brass, good cold and hot processability, castability, welding property and mechanical property.Can be widely used in the casting of optoelectronic components, household electrical appliances, automobile component of electronics, telecommunication, computer, tap water engineering, five metals, machinery, photographic apparatus and cold and hot moulding, easily cut the component production.

Bismuth and antimony are the elements of strengthening and improve the alloy cutting ability, based on bismuth, with the auxiliary bismuth of antimony.Bi content did not satisfy the machinability requirement less than 0.3% o'clock in this alloy, and bi content with reducing the hot and cold processability of alloy and the mechanical property of alloy sharply being descended, has also increased cost greater than 1.5% o'clock simultaneously.For making full use of the characteristic that bismuth can improve cutting ability, also to prevent the brittle failure tendency that excessive bismuth can cause hot and cold processability and mechanical property to descend simultaneously, the content of bismuth is 0.3～1.5% in alloy.Such content is controlled under the condition that does not contain other cutting elements such as antimony, the cutting coefficient of this alloy is reached about 80%, but be also to have added auxiliary antimony element simultaneously on 0.3～1.5% the basis at bi content, make it auxiliary bismuth and obtained more excellent cutting ability (cutting coefficient is 86～95%) and excellent corrosion resistant performance, mechanical property, and then reach the requirement of environmental protection, health, novel alloy material with the bismuth acting in conjunction.

The auxiliary antimony element that adds proper content mainly has been the effect that auxiliary bismuth further improves the cutting ability and the distinctive inhibition dezincify performance of alloy.When the interpolation content of antimony less than 0.05% the time, auxiliary bismuth is improved the cutting ability DeGrain, and it is not obvious to improving the anti dezincification character effect, and the auxiliary content that adds was greater than 1.0% o'clock, though it is bigger that auxiliary bismuth improves cutting ability, but it is also very obvious that the plasticity of this alloy reduces, and also increased cost simultaneously.So through facts have proved that the auxiliary content that adds antimony is 0.05～1.0%, just can play the effect that auxiliary bismuth improves the cutting ability of this alloy, make this alloy have more excellent cutting ability (cutting coefficient is 86～95%), anti dezincification character energy and good cold and hot processability, welding property and favorable mechanical performance.

The solubleness of bismuth in copper is extremely low, and bismuth also is to be present in the alloy with free state.But different with lead is, bismuth is to be present in the alloy with nontoxic free state, rather than resembles and be present in the alloy with deleterious free state the lead.Not to the limits value of bismuth, yet nobody points out that bismuth is harmful material in WHO (World Health Organization) the drinking-water quality control criterion.

The antimony of low levels all has certain solubleness in copper and zinc, so antimony is to be present in the alloy with the nontoxic solid solution attitude of low levels, and is water insoluble, rather than resemble and be present in the alloy with deleterious free state the lead.Through electronic probe and transmission electron microscope observing, preferential and the zinc formation sosoloid of antimony in this alloy, and accumulate near the crystal boundary, free machining short chip breaking point formed, make stibiated metallic compound embrittlement be evenly distributed on mutually on the crystal boundary, further improved the cutting ability of this alloy.

This alloy improves the anti dezincification character energy of alloy based on boron with auxiliary boron such as antimony, tin.Adding boron mainly has been the effect that suppresses dezincify, improves corrosion resisting property, and the function of deoxidation, crystal grain thinning, enhancing cutting ability is also arranged simultaneously.Because the boron atomic radius is littler than zinc atom radius; therefore the easier diffusion of boron atom ratio zinc atom when brass is corroded can preferentially be captured the room and then be stopped up the diffusion admittance of zinc atom, increases the resistance of zinc diffusion; form anti-corrosion protective membrane, thereby reach effect as the inhibition Dezincification corrosion of arsenic.Simultaneously antimony also easily and zinc form the Solid solution compound, can suppress dezincify equally, thereby play the auxiliary boron and the effect of acting in conjunction raising alloy anti dezincification character with it.

The add-on of boron is advisable 0.0002～0.05%.Boron content is less than 0.0002% o'clock, to suppressing dezincify and anti-corrosion DeGrain; Boron content was greater than 0.05% o'clock, and boride is easily separated out at crystal boundary, caused " boron is crisp ", reduced the alloy processability.

Except adding boron, in this brass, add other element such as trace tin and can further improve the anti dezincification character energy, make it to reach the leaching standard and the ISO6509 dezincify standard of coherent element in the copper alloy of international tap water mechanism defined.

Zinc content helps the raising of cutting ability and the enhancing of wear resisting property greater than 35.5%, but too high meeting influence cold forming capability and alloy strength.

The effect that at least two kinds of elements in titanium in described other element, nickel, iron, tin, phosphorus, the rare earth metal add, the one, deoxidation, crystal grain thinning; The 2nd, with the lead formation metallic compound in the impurity, strengthen crystal boundary, and make stibiated metallic compound embrittlement more tiny being evenly distributed on the crystal boundary mutually, and make bismuth metal be uniformly distributed in intracrystalline and crystal boundary, also can suppress the poly-brittle failure tendency of bismuth phase and stibiated embrittlement skew simultaneously, and then satisfy the cutting ability of the excellence of industrial needs, good cold and hot processability and welding property; The 3rd, suppress dezincify, strengthen corrosion resisting property and anti-stress fragility energy.Described other element total content does not reach satisfied cutting ability and grain-boundary strengthening effect less than 0.2%; Other element total amount though can make the further refinement of alloy, suppresses dezincify greater than 1.2%, can form other more hard crisp phase, does not satisfy the cold forming capability in back step, has also increased cost simultaneously, and effect is promoted the use of in influence.

Adding titanium mainly has been deoxidation and crystal grain thinning effect, and general addition is 0.001～0.15% to be advisable, and less than 0.001% DeGrain, can increase cost greater than 0.15%, and make the castability reduction.

Nickel is matrix strengthening and stops the dezincify element, suppresses grain growth simultaneously, increases alloy strength, plasticity and solidity to corrosion, also can improve the ability of alloy stress corrosion resistant simultaneously.Nickel content is less than 0.1%, is difficult to satisfy every performance requriements of industrial needs, and nickel content can increase the manufacturing cost of alloy again and reduce cutting ability greater than 0.6%, so nickel content should be controlled at 0.1～0.6%.

Iron mainly has been crystal grain thinning with rare earth metal, has stoped grain growth, control β to change the effect of quantity mutually, can improve softening temperature, strengthen intensity, improves cold and hot processability.Another vital role of rare earth metal is deoxidation.Iron level generally is controlled at 0.1～0.3%, and iron level is less than 0.1%, and grain refinement effect is not obvious; Iron level can reduce corrosion resisting property and electrodepositable performance greater than 0.3%.Rare earth metal is good alterant and refining scavenging agent, solid solution is in copper hardly, it can form high melting point metal compound with the impurity lead in the alloy, is distributed in intracrystalline, improves plasticity, the wear resistance of alloy, impel grain refining, facilitate the more tiny uniform distribution of metallic compound on the crystal boundary, general add-on is 0.003～0.4%, and adding with the lanthanum is the mishmetal better effects if of base, can increase electric conductivity and anti-dezincify ability, the too high flowability that can reduce alloy.

The same with antimony, add tin, phosphorus and also be auxiliary boron and strengthen the performance that anti-dezincify, anti-stress split and improve the thermo forming performance, make it to reach the standard of international environment protection health security regulations.Secondly in this brass, add the flowability of tin, all right deoxidation of phosphorus, increase alloy, improve the cutting ability and the intensity of alloy.Tin is solution strengthening and the element that suppresses dezincify, strengthen matrix together with antimony, boron, phosphorus, help being uniformly dispersed and the formation of strengthening phase of each phase, help the raising of intensity, wear resistance and cutting ability, particularly help anti dezincification character can and the raising of thermoforming performance.The content of phosphorus generally is controlled at 0.005～0.2% and is advisable.The content of tin generally is controlled at 0.1～0.4% and is advisable, and too high meeting reduces cutting ability.

Even lead and cadmium are as the unavoidable impurities element, the lead content in the impurity also must be less than 0.1%, and cadmium content must be less than 0.001%.According to the leaching amount detected result of the correlation detection standard in the international tap water engineering, this lead, cadmium content had both met international environmental protection and had ordered requirement within a certain time, caused public hazards can for again environment and human health.

One of above-mentioned lead-free free-cutting low antimony bismuth brass alloy of the present invention is to have excellent cutting ability, anti dezincification character energy, an anti-stress corrosion performance, good mechanical property and cold and hot processability and good welding property help environmental protection, healthy new type leadless easy cutting brass alloys.Can be widely used in the casting of optoelectronic components, household electrical appliances, automobile component of electronics, telecommunication, computer, tap water engineering, five metals, machinery, photographic apparatus and cold and hot moulding, easily cut the component production.

Two alloy composition of lead-free free-cutting low antimony bismuth brass alloy of the present invention is: copper: 55～63wt%, bismuth: 0.3～1.5wt%, antimony: 0.05～1.0wt%, nickel: 0.1～0.6wt%, boron: 0.0002～0.05wt%, other element: 0.2～1.5wt%, described other element is at least two kinds of elements that are selected from titanium, iron, silicon, tin, phosphorus, the rare earth metal, all the other are zinc and unavoidable impurities, and content plumbous in the unavoidable impurities is less than 0.1wt%; The copper zincification adds bismuth and adds antimony and add boron greater than 97wt% in the described alloy composition, and wherein zinc greater than 36.5wt%.

Two preferable consisting of of described lead-free free-cutting low antimony bismuth brass alloy: copper: 57～62wt%, bismuth: 0.4～1.4wt%, antimony: 0.06～0.8wt%, nickel: 0.1～0.5wt%, boron: 0.0006～0.03wt%, other element: 0.2～1.2wt%, described other element is at least two kinds of elements that are selected from titanium, iron, silicon, tin, phosphorus, the rare earth metal, all the other are zinc and unavoidable impurities, and content plumbous in the unavoidable impurities is less than 0.1wt%; The copper zincification adds bismuth and adds antimony and add boron greater than 97.5wt% and be not more than 99.8wt% in the described alloy composition, and wherein zinc is greater than 36.5wt%.

Two phase composite of described lead-free free-cutting low antimony bismuth brass alloy is: based on α, β two-phase, the bismuth that is uniformly distributed in intracrystalline and crystal boundary with free state mutually, a small amount of tiny hard crisp phase that contains compound between antimony metal that is uniformly distributed in the solid solution attitude of crystal boundary.

Two of described lead-free free-cutting low antimony bismuth brass alloy is to utilize bismuth and antimony to substitute lead, based on bismuth, further improves the cutting ability of alloy with the auxiliary bismuth of antimony; Based on boron, improve the anti dezincification character energy of alloy with auxiliary boron such as antimony, tin simultaneously.

The adding of bismuth can improve the machinability of alloy.The solid solubility of bismuth in copper is extremely low, even the solubleness in the time of 800 ℃ also only 0.01%, but the solubleness in the liquation is very big, bismuth precipitates in process of setting, form the second phase particle of disperse, the disperse phase fusing point of this bismuth lower (271.3 ℃), in the contact surface local heating of cutter head and bits and instant melting, this fuse effect helps to change the shape and the lubricated cutter of smear metal, make alloy in machining, easily form short chip breaking point thereby play, bonding between minimizing cutter head and the workpiece and seam and the effect that improves cutting speed, and then make alloy have satisfied cutting ability.But bi content was greater than 1.5% o'clock, can cause the brittle failure increase, our employing is that advocating peace with the antimony that adds easy formation sosoloid is the alloying scheme of assisting with the bismuth that adds low levels for this reason, make the stibiated metallic compound of easy cutting chip breaking (nontoxic with solid solution, healthy form is present in the alloy) embrittlement mutually also accumulates near the crystal boundary, make this alloy obtain more excellent cutting ability and other over-all properties, thereby reached based on bismuth, assist bismuth further to improve the purpose of the cutting ability of alloy with antimony, this alloy has been obtained as the excellent cutting ability of leaded brass.Add simultaneously some crystal grain thinnings again, suppress dezincify and control other element of trace that the alloy brittle failure is inclined to, and then make that stibiated metallic compound is more tiny to be evenly distributed on the crystal boundary, and make bismuth metal be uniformly distributed in intracrystalline and crystal boundary, make alloy in machining, easily form short chip breaking point, increased over-all propertieies such as the cutting ability of alloy and anti-corrosion anti dezincification character effectively, thereby made the low antimony bismuth brass alloys obtain to resemble cutting ability excellent the leaded brass, good thermoforming performance, castability, welding property and mechanical property.Can be widely used in the casting of optoelectronic components, household electrical appliances, automobile component of electronics, telecommunication, computer, tap water engineering, five metals, machinery, photographic apparatus and thermoforming, easily cut the component production.

Bismuth and antimony are the elements of strengthening and improve the alloy cutting ability, based on bismuth, with the auxiliary bismuth of antimony.Bi content did not satisfy the machinability requirement less than 0.3% o'clock in this alloy, and bi content reduced the hot and cold processability of alloy and the mechanical property of alloy is sharply descended greater than 1.5% o'clock, had also increased cost simultaneously.For making full use of the characteristic that bismuth can improve cutting ability, also to prevent the brittle failure tendency that excessive bismuth can cause hot and cold processability and mechanical property to descend simultaneously, the content of bismuth is 0.3～1.5% in alloy.Such content is controlled under the condition that does not contain other cutting elements such as antimony, the cutting coefficient of this alloy is reached about 80%, but be also to have added auxiliary antimony element simultaneously on 0.3～1.5% the basis at bi content, make it auxiliary bismuth and obtained more excellent cutting ability (cutting coefficient is 86～95%) and excellent corrosion resistant performance, mechanical property, and then reach the requirement of environmental protection, health, novel alloy material with the bismuth acting in conjunction.

The auxiliary antimony element that adds proper content mainly has been the effect that auxiliary bismuth further improves the cutting ability and the distinctive inhibition dezincify performance of alloy.When the interpolation content of antimony less than 0.05% the time, auxiliary bismuth is improved the cutting ability DeGrain, and it is not obvious to improving the anti dezincification character effect, and the auxiliary content that adds was greater than 1.0% o'clock, though it is bigger that auxiliary bismuth improves cutting ability, but it is also very obvious that the plasticity of this alloy reduces, and also increased cost simultaneously.So through facts have proved that the auxiliary content that adds antimony is 0.05～1.0%, just can play the effect that auxiliary bismuth improves the cutting ability of this alloy, make this alloy have more excellent cutting ability (cutting coefficient is 86～95%), anti dezincification character energy and good thermoforming performance, welding property and favorable mechanical performance.

Zinc content helps the raising of cutting ability and the enhancing of wear resisting property greater than 36.5%, but too high meeting influence cold forming capability and alloy strength.

The effect that at least two kinds of elements in titanium in described other element, iron, silicon, tin, phosphorus, the rare earth metal add, the one, deoxidation, crystal grain thinning; The 2nd, with the lead formation metallic compound in the impurity, strengthen crystal boundary, and make stibiated metallic compound embrittlement more tiny being evenly distributed on the crystal boundary mutually, and make bismuth metal be uniformly distributed in intracrystalline and crystal boundary, also can suppress the poly-brittle failure tendency of bismuth phase and stibiated embrittlement skew simultaneously, and then satisfy cutting ability, thermoforming performance and the good welding property of the excellence of industrial needs; The 3rd, suppress dezincify, strengthen corrosion resisting property and anti-stress fragility energy.Described other element total content does not reach satisfied cutting ability and grain-boundary strengthening effect less than 0.2%; Other element total amount though can make the further refinement of alloy, suppresses dezincify greater than 1.5%, can form other more hard crisp phase, does not satisfy the cold forming capability in back step, has also increased cost simultaneously, and effect is promoted the use of in influence.

Add silicon, the one, be used for improving casting and welding flowability, improve the welding technological properties of this alloy, particularly silicon can also suppress zinc evaporation and oxide inclusion in welding process; The 2nd, strengthen density and withstand voltage, the wear resisting property and the cutting ability of alloy, rather than make alloy generate the hard crisp phase of γ of high silicon.General add-on is 0.1～0.7%, when silicone content above-mentioned action effect less than 0.1% time not obvious; When silicone content can generate more embrittlement phases such as iron silicide greater than 0.7%, and make alloy brittle failure enhancing, cutting resistance increases.

The same with antimony, add tin, phosphorus and also be auxiliary boron and strengthen the performance that anti-dezincify, anti-stress split and improve the thermo forming performance, make it to reach the standard of international environment protection health security regulations.Secondly in this brass, add the flowability of tin, all right deoxidation of phosphorus, increase alloy, improve the cutting ability and the intensity of alloy.Tin is solution strengthening and the element that suppresses dezincify, strengthen matrix together with antimony, boron, phosphorus, help being uniformly dispersed and the formation of strengthening phase of each phase, help the raising of intensity, wear resistance and cutting ability, particularly help anti dezincification character can and the raising of cold and hot processability.The content of phosphorus generally is controlled at 0.005～0.2% and is advisable.The content of tin generally is controlled at 0.1～0.4% and is advisable, and too high meeting reduces cutting ability.

Even lead and cadmium are as the unavoidable impurities element, the lead content in the impurity must be less than 0.1%, and cadmium content must be less than 0.001%.According to the leaching amount detected result of the correlation detection standard in the international tap water engineering, this lead, cadmium content had both met international environmental protection and had ordered requirement within a certain time, caused public hazards can for again environment and human health.

Two of above-mentioned lead-free free-cutting low antimony bismuth brass alloy of the present invention is to have excellent cutting ability, anti-Dezincification corrosion performance, thermoforming performance and good castability, the new type leadless easy cutting brass alloys that help environment protection health, safety of favorable mechanical performance and welding property.Can be widely used in the casting of electronics, telecommunication, computer, tap water engineering, five metals, machinery, household electrical appliances, automobile component and forge hot heat is washed into type, easily cuts the component production.

Three alloy composition of lead-free free-cutting low antimony bismuth brass alloy of the present invention is: copper: 55～64wt%, bismuth: 0.3～1.5wt%, antimony: 0.05～1.0wt%, boron: 0.0002～0.05wt%, other element: 0.2～1.6wt%, described other element is at least two kinds of elements that are selected from titanium, nickel, iron, tin, phosphorus, the rare earth metal, all the other are zinc and unavoidable impurities, and content plumbous in the unavoidable impurities is less than 0.03wt%; The copper zincification adds bismuth and adds antimony and add boron greater than 97wt% in the described alloy composition, and wherein zinc greater than 35.5wt%.

Three preferable consisting of of described lead-free free-cutting low antimony bismuth brass alloy: copper: 58～63wt%, bismuth: 0.4～1.4wt%, antimony: 0.06～0.8wt%, boron: 0.0006～0.03wt%, other element: 0.2～1.3wt%, described other element is at least two kinds of elements that are selected from titanium, nickel, iron, tin, phosphorus, the rare earth metal, all the other are zinc and unavoidable impurities, and content plumbous in the unavoidable impurities is less than 0.03wt%; The copper zincification adds bismuth and adds antimony and add boron greater than 97.5wt% and be not more than 99.8wt% in the described alloy composition, and wherein zinc is greater than 35.5wt%.

Three phase composite of described lead-free free-cutting low antimony bismuth brass alloy is: based on α, β two-phase, the bismuth that is uniformly distributed in intracrystalline and crystal boundary with free state mutually, a small amount of tiny hard crisp phase that contains compound between antimony metal that is uniformly distributed in the solid solution attitude of crystal boundary.

Three of described lead-free free-cutting low antimony bismuth brass alloy is to utilize bismuth and antimony to substitute lead, based on bismuth, further improves the cutting ability of alloy with the auxiliary bismuth of antimony; Based on boron, improve the anti dezincification character energy of alloy with auxiliary boron such as antimony, tin simultaneously.

The adding of bismuth can improve the machinability of alloy.The solid solubility of bismuth in copper is extremely low, even the solubleness in the time of 800 ℃ also only 0.01%, but the solubleness in the liquation is very big, bismuth precipitates in process of setting, form the second phase particle of disperse, the disperse phase fusing point of this bismuth lower (271.3 ℃), in the contact surface local heating of cutter head and bits and instant melting, this fuse effect helps to change the shape and the lubricated cutter of smear metal, make alloy in machining, easily form short chip breaking point thereby play, bonding between minimizing cutter head and the workpiece and seam and the effect that improves cutting speed, and then make alloy have satisfied cutting ability.But bi content was greater than 1.5% o'clock, can cause the brittle failure increase, our employing is that advocating peace with the antimony that adds easy formation sosoloid is the alloying scheme of assisting with the bismuth that adds low levels for this reason, make the stibiated metallic compound of easy cutting chip breaking (nontoxic with solid solution, healthy form is present in the alloy) embrittlement mutually also accumulates near the crystal boundary, make this alloy obtain excellent cutting ability and other over-all properties, thereby reached based on bismuth, assist bismuth further to improve the purpose of the cutting ability of alloy with antimony, this alloy has been obtained as the excellent cutting ability of leaded brass.Add simultaneously some crystal grain thinnings again, other element of trace that suppresses dezincify and control alloy brittle failure tendency, and then make that stibiated metallic compound is more tiny to be evenly distributed on the crystal boundary, and make bismuth metal be uniformly distributed in intracrystalline and crystal boundary, make alloy in machining, easily form short chip breaking point, increased over-all propertieies such as the cutting ability of alloy and anti-corrosion anti dezincification character effectively, thereby made the low antimony bismuth brass alloys obtain to resemble excellent cutting ability the leaded brass, good cold and hot processability, castability, welding property and mechanical property and the wholesomeness of more being strict with.Can be widely used in the casting of optoelectronic components, household electrical appliances, automobile component of electronics, telecommunication, computer, tap water engineering, five metals, machinery, photographic apparatus and cold and hot moulding, easily cut the component production.

The effect that at least two kinds of elements in titanium in described other element, nickel, iron, tin, phosphorus, the rare earth metal add, the one, deoxidation, crystal grain thinning; The 2nd, with the lead formation metallic compound in the impurity, strengthen crystal boundary, and make stibiated metallic compound embrittlement more tiny being evenly distributed on the crystal boundary mutually, also can suppress the poly-brittle failure tendency of bismuth phase and stibiated embrittlement skew simultaneously, and then satisfy the good cutting performance of industrial needs, good cold and hot processability and welding property; The 3rd, suppress dezincify, strengthen corrosion resisting property and anti-stress fragility energy.Described other element total content does not reach satisfied cutting ability and grain-boundary strengthening effect less than 0.2%; Other element total amount though can make the further refinement of alloy, suppresses dezincify greater than 1.6%, can form other more hard crisp phase, does not satisfy the cold forming capability in back step, has also increased cost simultaneously, and effect is promoted the use of in influence.

Even lead and cadmium are as the unavoidable impurities element, the lead content in the impurity must be less than 0.03%, and cadmium content must be less than 0.001%.This lead, cadmium content had both met international environmental protection and had ordered requirement within a certain time, caused public hazards can for again environment and human health, and adapt to environmental friendly material development trend in the future.

Three of above-mentioned lead-free free-cutting low antimony bismuth brass alloy of the present invention is anti-Dezincification corrosion performance, the anti-stress corrosion performances with good cutting performance, excellence, the new type leadless easy cutting brass alloys with the wholesomeness of more being strict with that help environmental protection, health of good cold and hot processability, mechanical property and welding property.Can be widely used in the casting of optoelectronic components, toy for children, household electrical appliances, automobile component of electronics, telecommunication, computer, tap water engineering, five metals, machinery, photographic apparatus and cold and hot moulding, easily cut the component production.

After adding elements such as bismuth, antimony, boron three kinds of lead-free free-cutting low antimony bismuth brass alloys invention of three from one of above-mentioned lead-free free-cutting low antimony bismuth brass alloy of the present invention to above-mentioned lead-free free-cutting low antimony bismuth brass alloy of the present invention, machinability, solidity to corrosion and anti dezincification character improve widely.The disperse phase particle that the brass alloys that these copper contents are lower contain α phase, β phase, bismuth is hard mutually crisp with other a spot of compound that contains between antimony metal, tinyly be evenly distributed on crystal boundary and intracrystalline and the precipitation strength effect is arranged, improved the cutting ability of alloy, increase the chip breaking point of short bits, also strengthened solidity to corrosion, anti dezincification character, wear resistance, mechanical property and the cold and hot processability of alloy simultaneously.

The manufacture method of alloy of the present invention is with weight %: copper: 55～65wt%; bismuth: 0.3～1.5wt%; antimony: 0.05～1.0wt%; boron: 0.0002～0.05wt%; other element: 0.2～1.2wt%; all the other are the alloying constituent that zinc and unavoidable impurities are constituted; adopt Alloying Treatment and covering protection method melting low antimony bismuth brass alloys; make boron; antimony quick solid solution in the brass liquation is an intermetallic compound; and make bismuth metal be uniformly distributed in intracrystalline and crystal boundary; and (the whole fusion process top temperature of this brass is 1080 ℃ to be continuously cast into ingot casting under 1040 ℃; do not reach 1675 ℃ of boiling temperatures that make metallic antimony evaporation far away and make 1680 ℃ of the boiling temperatures of bismuth metal evaporation; so work the mischief can not for the mankind and environment); under 680～760 ℃ of temperature, carry out the large extrusion ratio extruding; intermediate heat treatment is carried out under 500～700 ℃ of temperature by cold worked condition, is being lower than the annealing that can eliminate stress under 400 ℃ the temperature.

Compared with prior art, the invention has the advantages that: 1. have extremely excellent cutting ability, excellent anti dezincification character energy, good welding property, good solidity to corrosion, mechanical property, be specially adapted to the component, forging, foundry goods of machining moulding and as the component material of other manufacture method; 2. low cost of manufacture only is equivalent to the manufacturing cost of the leaded brass of prior art, thereby has market competition advantage; 3. can reach international environmental protection, health, safety standards code requirement fully, and the lead-free free-cutting low antimony bismuth brass alloy material of another novel environment friendly, health is provided for world's recycling economy.

Description of drawings

Fig. 1, be the car of alloy of the present invention bits pattern synoptic diagram, the turning back engagement of the cutting edge is 0.5mm, and the speed of mainshaft is 900rpm/min, and the amount of feed is 0.1mm/rev.

Embodiment

Below in conjunction with embodiment invention is described in further detail:

Embodiment forms ingot casting, pushes, is drawn into pole by the alloy ingredient in following each table lead-free free-cutting low antimony bismuth brass alloy of the present invention; The contrast sample is the Winn bronze trade mark C36000 alloy of the U.S., and it is the universally acknowledged best Winn bronze of machinability (100%), also carries out same shaping.

Its technological process of production method is as follows:

Starting material are prepared and batching, and---------------stretching,------------aligning polishing---stress relieving---check finished product packing stretches in pickling in thermal treatment in extruding in the ingot casting heating in continuous casting in the Alloying Treatment melting.

Specifically can be expressed as follows: adopt Alloying Treatment and covering protection method melting low antimony bismuth brass alloys; making the quick solid solution in the brass liquation of boron, antimony is intermetallic compound; and make bismuth metal be uniformly distributed in intracrystalline and crystal boundary; and under 1040 ℃, be continuously cast into ingot casting; under 680～760 ℃ of temperature, carry out the large extrusion ratio extruding; intermediate heat treatment is carried out under 500～700 ℃ of temperature by cold worked condition, is being lower than the annealing that can eliminate stress under 400 ℃ the temperature.

Wherein changing process of thermal treatment flow implementation process over to proves, thermal treatment is lower than 400 ℃ stress relieving and can carries out, and that intermediate heat treatment needs to be annealed under 500～700 ℃ of temperature according to cold worked condition is suitable, but warm brittle zone annealing in should as far as possible avoiding (its flow process is produced identical with the lead brass alloy of routine substantially).

It is of a size of Φ 170*400～500 millimeter the ingot casting of the various serial invention alloy of lead-free free-cutting low antimony bismuth brass alloy of the present invention, under 680 ℃～760 ℃ of identical appointed condition and different extrusion temperatures, be squeezed into the wire rod of 10 millimeters of Φ 9, Φ, its concrete component content sees Table 11, shown in the table 12, table 13.

Table 11: the composition of one of invention of lead-free free-cutting low antimony bismuth brass alloy of the present invention is formed example: (weight %)

Table 12: two composition of the invention of lead-free free-cutting low antimony bismuth brass alloy of the present invention is formed example: (weight %)

??2-007	??59.98	??0.92	??0.31	??0.16	??0.0028	Surplus	??0.0012	??---	??0.205	??0.106	??---	≤ 0.2, (wherein Pb＜0.1, Cd＜0.001)
??2-007	??59.98	??0.92	??0.31	??0.16	??0.0028	Surplus	??0.0012	??---	??0.205	??0.106	??---	≤ 0.2, (wherein Pb＜0.1, Cd＜0.001)	??2-008	??60.33	??1.14	??0.25	??0.11	??0.0035	Surplus	??---	??0.124	??0.163	??---	??0.0103	≤ 0.2, (wherein Pb＜0.1, Cd＜0.001)
??2-009	??60.47	??1.03	??0.12	??0.13	??0.0018	Surplus	??---	??0.196	??---	??---	??0.0217	≤ 0.2, (wherein Pb＜0.1, Cd＜0.001)	??2-008	??60.33	??1.14	??0.25	??0.11	??0.0035	Surplus	??---	??0.124	??0.163	??---	??0.0103	≤ 0.2, (wherein Pb＜0.1, Cd＜0.001)
??2-009	??60.47	??1.03	??0.12	??0.13	??0.0018	Surplus	??---	??0.196	??---	??---	??0.0217	≤ 0.2, (wherein Pb＜0.1, Cd＜0.001)	??2-010	??62.72	??1.26	??0.54	??0.12	??0.0265	Surplus	??0.0014	??---	??0.128	??---	??0.1325	≤ 0.2, (Pb＜0.1 wherein, Cd＜0.001=

Table 13: three composition of the invention of lead-free free-cutting low antimony bismuth brass alloy of the present invention is formed example: (weight %)

The performance test of lead-free free-cutting low antimony bismuth brass alloy of the present invention is as follows:

1. machinability experiment

Estimate by turning that the experiment of machinability is performed such:

Under identical mechanical workout condition, (see Table 14), adopt the cutting force experiment instrument to record the cutting force of each invention alloy, and calculate the machinability index of each invention alloy phase thus for C36000, C36000 is the universally acknowledged best Winn bronze of machinability, and its machinability is considered to 100%.The results are shown in Table 15, the car bits pattern of the correspondence that obtains as shown in Figure 1.

Table 14 is estimated the mechanical workout condition of machinability

The lathe model	Diameter of work (mm)	Back engagement of the cutting edge (mm)	The amount of feed (mm/r)	Cutting speed (m/min)	The speed of mainshaft (r/min)	Cut count (point)	Cutting state
The lathe model	Diameter of work (mm)	Back engagement of the cutting edge (mm)	The amount of feed (mm/r)	Cutting speed (m/min)	The speed of mainshaft (r/min)	Cut count (point)	Cutting state	??CA6140	??Φ7.3	??0.5	??0.1	??20.64	??900	??3	Do

Table 15 machinability evaluation result

Alloy	Machinability index (%)
Alloy	Machinability index (%)	??C36000	??100
Invent an alloy	??≥89	??C36000	??100
Invent an alloy	??≥89	Invent two alloys	??≥88
Invent three alloys	??≥95	Invent two alloys	??≥88

Annotate: cutting resistance * 100% of [machinability index]=[cutting resistance of C36000]/each invention alloy, each cutting resistance are according to the measured cutting force mean value value of experiment.

As seen, the machinability of alloy of the present invention can reach more than 88% of traditional Winn bronze C36000, the cutting ability excellence.

Except C36000, alloy of the present invention is that the Cu-Zn-Si of alloy, Japanese Triratna company is that alloy contrasts with the Cu-Zn-Bi of U.S. NAKAYAMA company also, by cutting, boring processing, obtain the comprehensive cutting ability of machining of invention alloy, the results are shown in Table 16.

The comprehensive cutting ability contrast of the machining of table 16 invention alloy and comparative alloy

2. thermo compression experiment

From first to the 3rd invention alloy extrudes respectively to be got Φ 9*20mm and makees sample on the product, contrast sample C36000 in addition and also get same size, does the thermo compression test.Sample axially loads then 670 ℃ of heating 30 minutes, and deflection is 70%, and length is reduced to 6mm by 20mm, observes its distortion rear surface crackle situation under 5～10 times of magnifying glasses.

We can see that after the thermo compression experiment, the surface of invention alloy and C36000 alloy is flawless all.As seen the hot workability of invention alloy and C36000 quite or better are fit to industrial processes.

3. dezincify experiment

Three carried out the dezincify experiment according to ISO6509 dezincify experimental technique from one of lead-free free-cutting low antimony bismuth brass alloy of the present invention invention to invention, contrasting sample is the C36000 Winn bronze, and the maximum Dezincification corrosion degree of depth that records sees Table 17:

Table 17: the maximum Dezincification corrosion depth correlation of lead-free free-cutting low antimony bismuth brass alloy of the present invention and C36000 Winn bronze

Alloy	The maximum dezincify degree of depth (μ m)
Alloy	The maximum dezincify degree of depth (μ m)	??C36000	??≥600

One of the present invention	??≤120
One of the present invention	??≤120	The present invention's two	??≤80
The present invention's three	??≤100	The present invention's two	??≤80

As seen from Table 17, the anti dezincification character of lead-free free-cutting low antimony bismuth brass alloy of the present invention all is better than the C36000 Winn bronze.

4. stress etching experiment

According to the ISO6957 experimental technique, lead-free free-cutting low antimony bismuth brass alloy of the present invention has been carried out stress etching experiment, the contrast sample is the C36000 Winn bronze.

After the test of 24 hours ammonia cures, take out sample, several minutes is fully cleaned in rinsing in distilled water water earlier then in the sulphuric acid soln 5% under the room temperature, at last washing and drying up in distilled water again.Through the specimen surface behind 10 times the amplifications observation ammonia cure, can see that behind stress etching experiment, lead-free free-cutting low antimony bismuth brass alloy of the present invention and C36000 Winn bronze surface all do not have obvious naked eyes visible crack.

5. normal temperature tension experiment

Getting one of lead-free free-cutting low antimony bismuth brass alloy of the present invention is the half-hard state finished product of Φ 5.0*140mm to three specification of lead-free free-cutting low antimony bismuth brass alloy of the present invention, carries out the normal temperature tension test, and the contrast sample is the C36000 Winn bronze with the state same specification.Test the unit elongation and the tensile strength of each invention alloy, the results are shown in Table 18.

Table 18: the normal temperature mechanical property contrast of lead-free free-cutting low antimony bismuth brass alloy of the present invention and C36000 Winn bronze

Alloy	Specification	State	Unit elongation (%)	Tensile strength (MPa)
Alloy	Specification	State	Unit elongation (%)	Tensile strength (MPa)	?C36000	?Φ5.0	?Y/2	?7	?≥450
One of invention	?Φ5.0	?Y/2	?6	?≥450	?C36000	?Φ5.0	?Y/2	?7	?≥450
One of invention	?Φ5.0	?Y/2	?6	?≥450	Two of invention	?Φ5.0	?Y/2	?5	?≥450
Three of invention	?Φ5.0	?Y/2	?6	?≥450	Two of invention	?Φ5.0	?Y/2	?5	?≥450

As seen from Table 18, the mechanical property of lead-free free-cutting low antimony bismuth brass alloy of the present invention is suitable substantially with traditional Winn bronze C36000.

6. conductivity test

Get lead-free free-cutting low antimony bismuth brass alloy of the present invention and C36000 Winn bronze, test its conductivity at room temperature rate, test result such as table 19:

The conductivity at room temperature rate contrast of table 19 lead-free free-cutting low antimony bismuth brass alloy of the present invention and C36000 Winn bronze

Alloy	??IACS(％)
Alloy	??IACS(％)	??C36000	??≥23
One of invention	??≥23	??C36000	??≥23
One of invention	??≥23	Two of invention	??≥23
Three of invention	??≥24	Two of invention	??≥23

7. differential thermal analysis (DTA)

Get lead-free free-cutting low antimony bismuth brass alloy of the present invention and C36000 and make differential thermal analysis, record fusing point and see Table 20:

The fusing point contrast of table 20 lead-free free-cutting low antimony bismuth brass alloy of the present invention and C36000 Winn bronze

Alloy	Fusing point (℃)
Alloy	Fusing point (℃)	??C36000	??900～910
One of invention	??910～920	??C36000	??900～910
One of invention	??910～920	Two of invention	??920～930
Three of invention	??910～920	Two of invention	??920～930

8. wholesomeness check

According to " Drinking Water transmission ﹠ distribution wetting system and protective material hygienic safety value disciplines " (2001), three of lead-free free-cutting low antimony bismuth brass alloy of the present invention has been carried out the wholesomeness check, assay sees Table 21:

Table 21 non-leaded easily-cutting brass-low antimony bismuth brass tap water immersion test increases survey project result

Sequence number	Analysis project	The hygienic practice requirement	Assay
Sequence number	Analysis project	The hygienic practice requirement	Assay	??1	Copper	Increasing amount≤0.2mg/L	Qualified
??2	Zinc	Increasing amount≤0.2mg/L	Qualified	??1	Copper	Increasing amount≤0.2mg/L	Qualified
??2	Zinc	Increasing amount≤0.2mg/L	Qualified	??3	Antimony	Increasing amount≤0.0005mg/L	Qualified

Take all factors into consideration various experimental results, we think that lead-free free-cutting low antimony bismuth brass alloy of the present invention is close with traditional Winn bronze cutting ability, the bismuth yellow brass that ratio is is abroad researched and developed in the recent period, the cutting ability excellence of siliceous 3% brass, phase composite also has its unique distinction in the formation of the cutting of alloy of the present invention reinforcement simultaneously mechanism, alloy principal constituent and the alloy.

Above-mentioned various experimental result also proves, the cutting ability of lead-free free-cutting low antimony bismuth brass alloy of the present invention, physical strength and excellent corrosion-proof performance.And raw materials cost is lower more than 5% than the generic no lead brass alloy (Cu-Zn-Bi alloy) of the U.S.; Generic no lead brass alloy (Cu-Zn-Si alloy) than Japanese Triratna is low more than 11%; But than traditional C36000 Winn bronze raw materials cost slightly high 2%.

Therefore lead-free free-cutting low antimony bismuth brass alloy of the present invention is a kind of leadless free-cutting brass alloy with excellent in machinability energy, corrosion resisting property, anti dezincification character energy, good mechanical property.Can be widely used in the component, heat exchanger web member, light fixture spare, gasburner of the foundry goods of component, domestic water supply system of the fastening piece of high-strength abrasion-proof of electronics, telecommunication, computer, household electrical appliances, five metals cutting component, forging, foundry goods and other purposes and hydraulic efficiency plant and valve, switch, water tap, automobile and instrument industries etc., all have very high use value, also satisfied the standard-required of international ecological environment protection health safety and sanitation standards simultaneously.

Claims

1. ecological, environmental protective new type leadless easy cutting low antimony bismuth brass alloys, it is characterized in that: it is by copper, zinc and bismuth, boron, alloying elements such as antimony become to be grouped into unavoidable impurities, consisting of of described alloy: copper: 55～65wt%, bismuth: 0.3～1.5wt%, antimony: 0.05～1.0wt%, boron: 0.0002～0.05wt%, other element: 0.2～1.2wt%, described other element is to be selected from titanium, nickel, iron, tin, phosphorus, at least two kinds of elements in the rare earth metal, all the other are zinc and unavoidable impurities, and content plumbous in the unavoidable impurities is less than 0.1wt%; The copper zincification adds bismuth and adds antimony and add boron greater than 97wt% in the described alloy composition, and wherein zinc greater than 35.5wt%.

2. lead-free free-cutting low antimony bismuth brass alloy according to claim 1, it is characterized in that: the consisting of of described alloy: copper: 58～63wt%, bismuth: 0.4～1.4wt%, antimony: 0.06～0.8wt%, boron: 0.0006～0.03wt%, other element: 0.2～1.0wt%, described other element is at least two kinds of elements that are selected from titanium, nickel, iron, tin, phosphorus, the rare earth metal, all the other are zinc and unavoidable impurities, and content plumbous in the unavoidable impurities is less than 0.1wt%; The copper zincification adds bismuth and adds antimony and add boron greater than 97.5wt% and be not more than 99.8wt% in the described alloy composition, and wherein zinc is greater than 35.5wt%.

3. ecological, environmental protective new type leadless easy cutting low antimony bismuth brass alloys, it is characterized in that consisting of of alloy: copper: 55～63wt%, bismuth: 0.3～1.5wt%, antimony: 0.05～1.0wt%, nickel: 0.1～0.6wt%, boron: 0.0002～0.05wt%, other element: 0.2～1.5wt%, described other element is at least two kinds of elements that are selected from titanium, iron, silicon, tin, phosphorus, the rare earth metal, all the other are zinc and unavoidable impurities, and content plumbous in the unavoidable impurities is less than 0.1wt%; The copper zincification adds bismuth and adds antimony and add boron greater than 97wt% in the described alloy composition, and wherein zinc greater than 36.5wt%.

4. lead-free free-cutting low antimony bismuth brass alloy according to claim 3, it is characterized in that: the consisting of of described alloy: copper: 57～62wt%, bismuth: 0.4～1.4wt%, antimony: 0.06～0.8wt%, nickel: 0.1～0.5wt%, boron: 0.0006～0.03wt%, other element: 0.2～1.2wt%, described other element is at least two kinds of elements that are selected from titanium, iron, silicon, tin, phosphorus, the rare earth metal, all the other are zinc and unavoidable impurities, and content plumbous in the unavoidable impurities is less than 0.1wt%; The copper zincification adds bismuth and adds antimony and add boron greater than 97.5wt% and be not more than 99.8wt% in the described alloy composition, and wherein zinc is greater than 36.5wt%.

5. ecological, environmental protective new type leadless easy cutting low antimony bismuth brass alloys, it is characterized in that consisting of of alloy: copper: 55～64wt%, bismuth: 0.3～1.5wt%, antimony: 0.05～1.0wt%, boron: 0.0002～0.05wt%, other element: 0.2～1.6wt%, described other element is at least two kinds of elements that are selected from titanium, nickel, iron, tin, phosphorus, the rare earth metal, all the other are zinc and unavoidable impurities, and content plumbous in the unavoidable impurities is less than 0.03wt%; The copper zincification adds bismuth and adds antimony and add boron greater than 97wt% in the described alloy composition, and wherein zinc greater than 35.5wt%.

6. lead-free free-cutting low antimony bismuth brass alloy according to claim 5, it is characterized in that: the consisting of of described alloy: copper: 58～63wt%, bismuth: 0.4～1.4wt%, antimony: 0.06～0.8wt%, boron: 0.0006～0.03wt%, other element: 0.2～1.3wt%, described other element is at least two kinds of elements that are selected from titanium, nickel, iron, tin, phosphorus, the rare earth metal, all the other are zinc and unavoidable impurities, and content plumbous in the unavoidable impurities is less than 0.03wt%; The copper zincification adds bismuth and adds antimony and add boron greater than 97.5wt% and be not more than 99.8wt% in the described alloy composition, and wherein zinc is greater than 35.5wt%.

7. according to the described lead-free free-cutting low antimony bismuth brass alloy of arbitrary claim in the claim 1 to 6, it is characterized in that: the content of described iron is 0.1～0.3wt%.

8. according to the described lead-free free-cutting low antimony bismuth brass alloy of arbitrary claim in the claim 1 to 6, it is characterized in that: the content of described tin is 0.1～0.4wt%.

9. according to claim 3 or 4 described lead-free free-cutting low antimony bismuth brass alloys, it is characterized in that: the content of described silicon is 0.1～0.7wt%.

10. the method for a manufacturing such as claim 1 or 3 or 5 described lead-free free-cutting low antimony bismuth brass alloys; it is characterized in that: its manufacturing processed is: adopt Alloying Treatment and covering protection method melting low antimony bismuth brass alloys; make boron; antimony quick solid solution in the brass liquation is an intermetallic compound; and make bismuth metal be uniformly distributed in intracrystalline and crystal boundary; and under 1040 ℃, be continuously cast into the brass ingot casting; under 680～760 ℃ of temperature, carry out the large extrusion ratio extruding; intermediate heat treatment is carried out under 500～700 ℃ of temperature by cold worked condition, is being lower than the annealing that can eliminate stress under 400 ℃ the temperature.