CN113073226A - Cu-TiC electric contact composite material and preparation method thereof - Google Patents
Cu-TiC electric contact composite material and preparation method thereof Download PDFInfo
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- CN113073226A CN113073226A CN202110317786.XA CN202110317786A CN113073226A CN 113073226 A CN113073226 A CN 113073226A CN 202110317786 A CN202110317786 A CN 202110317786A CN 113073226 A CN113073226 A CN 113073226A
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C9/00—Alloys based on copper
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C1/00—Making non-ferrous alloys
- C22C1/04—Making non-ferrous alloys by powder metallurgy
- C22C1/05—Mixtures of metal powder with non-metallic powder
- C22C1/058—Mixtures of metal powder with non-metallic powder by reaction sintering (i.e. gasless reaction starting from a mixture of solid metal compounds)
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C32/00—Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ
- C22C32/0047—Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ with carbides, nitrides, borides or silicides as the main non-metallic constituents
- C22C32/0052—Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ with carbides, nitrides, borides or silicides as the main non-metallic constituents only carbides
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H1/00—Contacts
- H01H1/02—Contacts characterised by the material thereof
- H01H1/021—Composite material
- H01H1/025—Composite material having copper as the basic material
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H11/00—Apparatus or processes specially adapted for the manufacture of electric switches
- H01H11/04—Apparatus or processes specially adapted for the manufacture of electric switches of switch contacts
- H01H11/048—Apparatus or processes specially adapted for the manufacture of electric switches of switch contacts by powder-metallurgical processes
Abstract
The invention discloses a Cu-TiC reinforced electric contact composite material and a preparation method thereof, and the Cu-TiC reinforced electric contact composite material specifically comprises the following steps: and carrying out ball milling and mixing on titanium powder, graphite powder and copper powder to obtain Cu-Ti-graphite mixed powder, carrying out cold press molding on the mixed powder, and carrying out step sintering in a hot press sintering furnace to obtain the Cu-TiC electric contact composite material. In the Cu-TiC enhanced electric contact composite material, TiC is synthesized by a self-generated reaction and well combined with a copper matrix interface, TiC reinforcements in the prepared composite material are distributed in a continuous network shape, the copper matrix is distributed among the TiC networks to form a continuous conductive phase, and the prepared composite material has obviously improved fusion welding resistance, arc ablation resistance and mechanical wear resistance and has excellent electric conduction and heat conduction performances.
Description
Technical Field
The invention relates to the technical field of electrical materials, in particular to a Cu-TiC electric contact composite material and a preparation method thereof.
Background
The electric contact material is an important component of an electrical material, and an electric contact prepared by the electric contact material is an important contact element in instruments and meters and electric switches, and plays a role in breaking and connecting circuits in power transmission and distribution systems, electric systems and the like. The quality of the electrical contact and the material performance thereof plays an important role in the safe and stable operation of the whole system.
Copper has excellent electrical conductivity and thermal conductivity and is a common electric contact material, but the pure copper has low hardness, strength and the like, so that the copper has insufficient arc erosion resistance, mechanical abrasion resistance and the like when being used as the electric contact material, and the application of the copper in a strong arc ablation environment is limited. Alloying and compounding are common methods for improving the mechanical property of copper, for example, Cu-Cr and Cu-W alloys formed by copper, chromium and tungsten have excellent mechanical property while maintaining good electric and thermal conductivity of copper, and are the main current electric contact materials for high-voltage circuit breakers. For example, patent CN109261961B discloses a method for preparing a Cu-Cr electrical contact material based on 3D printing technology, which is to prepare a composite contact material with a diversion microstructure composed of a high conductive phase Cu, an arc ablation resistant phase Cr, and a soft magnetic phase Fe, to change the diversion phase and the arc ablation resistant phase from disorder to order, so as to form a micro structural unit inside the contact, thereby improving the breaking current capability and the voltage breakdown resistant capability of the contact. In the copper-based composite material, the composite material is divided into a fiber continuous reinforced copper-based composite material, a whisker semi-continuous reinforced copper-based composite material, a particle reinforced discontinuous copper-based composite material and the like according to the difference of a reinforcement, and the addition of the reinforcement can effectively improve the strength, hardness and wear resistance of the material in any type of composite material. For example, patent CN102426867A discloses a whisker reinforced copper-based electrical contact material and a preparation method thereof, and a silicon carbide whisker or zinc oxide whisker reinforced copper-based composite material is prepared, wherein the whisker has a dispersion strengthening effect and a small influence on the electrical conductivity of the material, and can play a good role in fusion welding resistance, arc ablation resistance, oxidation resistance, especially high-temperature oxidation resistance, wear resistance improvement, contact resistance improvement, temperature rise reduction, electrical life improvement and the like when used as a contact for high and low voltage electrical appliances. Patent CN108531766A discloses a binary conductive oxide modified copper-based electrical contact material and a preparation method thereof, which utilizes the strengthening effect of the binary conductive oxide to obtain a novel stable copper-based electrical contact material with high arc erosion resistance and low contact resistance. In recent years, with the development of the fields of ultrahigh voltage transmission lines, high speed trains, electromagnetic rail guns and the like in China, higher requirements are put forward on electric contact materials for high voltage circuit breaker arc contacts, high speed train pantograph slide plates and the like, electromagnetic rail gun guide rails and the like, and development of novel electric contact materials is urgently needed.
In the copper-based electric contact composite material, TiC has high melting point, hardness, thermal stability and certain electric and heat conductivity, so that TiC is an ideal reinforcement for developing a high-strength high-electric-conductivity copper electric contact material. The existing TiC reinforced copper-based composite material is a TiC particle reinforced discontinuous copper-based composite material, the hardness, the strength and the wear resistance of the copper-based composite material can be effectively improved due to the existence of TiC particles, and if the TiC can form a continuous network and be combined with copper to form the composite material, the TiC reinforced copper-based composite material is more favorable for playing the role of TiC reinforcement.
Disclosure of Invention
In order to solve the problems, the invention fully mixes graphite powder and titanium powder, carries out cold press molding, adds the mixture into copper melt, controls the reaction process of a Cu-Ti-C system in the infiltration process of the copper melt, leads TiC generated by the autogenous reaction to be mutually connected to form a continuous network, introduces a copper matrix between the networks, and further carries out hot press sintering to obtain a compact Cu-TiC electric contact composite material, wherein the Cu-TiC electric contact composite material is prepared from the following raw materials in percentage by mass:
1-10% of graphite powder, 4-40% of titanium powder and the balance of copper powder;
the granularity of the titanium powder is 5-200 mu m, the granularity of the graphite powder is 1-50 mu m, and the granularity of the copper powder is 1-300 mu m;
the TiC in the electric contact composite material forms a continuous network-shaped reinforcement in a network shape.
The invention also provides a preparation method of the Cu-TiC electric contact composite material, which comprises the following steps:
(1) preparing raw materials: weighing titanium powder, graphite powder and copper powder according to mass percentage;
(2) mixing raw materials: dividing copper powder into two parts, firstly, uniformly mixing graphite powder and the first part of copper powder in an argon atmosphere, and then fully mixing the graphite powder and the first part of copper powder with titanium powder and the rest copper powder to obtain Cu-Ti-graphite mixed powder;
(3) cold press molding: cold-pressing the Cu-Ti-graphite mixed powder into a cylindrical prefabricated block;
(4) hot-pressing and sintering: and (4) placing the cold-pressed precast block in a vacuum hot-pressing sintering furnace, and performing hot-pressing sintering to obtain the finished composite material.
Further, in the step (2), the copper powder is divided into two parts, the mass ratio of the first part of copper powder to the graphite is 4-15:1, and the rest is the second part of copper powder.
Further, step (2) is to mix graphite powder and the first part of copper powder for 2-10 hours under the argon atmosphere.
Further, the pressure of the cold press molding in the step (3) is 50-100 MPa.
Further, the vacuum hot-pressing sintering step in the step (4) is as follows:
1) carrying out hot-pressing sintering on the cold-pressed precast block under the pressure of 100-300MPa, wherein the sintering temperature is 850-950 ℃, and the sintering time is 0.5-2 h;
at this stage, the copper and the titanium in the raw materials firstly react to form eutectic with low melting point, and the unreacted graphite is coated;
2) step 1), after sintering, raising the temperature to 1050-;
at this stage, the titanium in the raw materials and the graphite fully react to form TiC and realize the densification of the block body, and finally the finished product composite material is obtained.
The invention self-generates continuous network TiC through the reaction of Ti-C in the copper melt under the semi-solid condition, prepares the Cu-TiC electric contact composite material taking the continuous network TiC as the reinforcement, further improves the arc ablation resistance, the mechanical abrasion resistance and the breaking capacity of the Cu-TiC electric contact composite material by fully playing the reinforcing function of the TiC, and better meets the performance requirements of the electric contact material under the working conditions of extra-high voltage, large current and the like.
Compared with the prior art, the invention has the beneficial technical effects that:
the TiC is synthesized by the autogenous reaction and well combined with the interface of the copper matrix, the TiC reinforcement in the prepared composite material is distributed in a continuous network shape, the copper matrix is distributed among the TiC networks and used as a conductive phase, so that the fusion welding resistance, the arc ablation resistance and the mechanical wear resistance of the prepared composite material are obviously improved, and the composite material has excellent conductive and heat-conducting properties and good application prospect.
Drawings
The invention is further illustrated in the following description with reference to the drawings.
FIG. 1 is a microstructure of a Cu-TiC electrical contact composite prepared in example 1;
FIG. 2 shows the microstructure of TiC etched back in the Cu-TiC electrical contact composite material prepared in example 1.
Detailed Description
The Cu-TiC electrical contact composite material provided by the invention is further illustrated by combining the embodiment.
Example 1
(1) Preparing raw materials: weighing titanium powder with the granularity of 5 mu m and the purity of more than 99 percent according to the mass percent: 24% of graphite powder with the granularity of 50 μm and the purity of more than 99%: 6 percent of copper powder with the granularity of 50 mu m and the purity of more than 99.5 percent;
(2) mixing raw materials: firstly, uniformly mixing graphite powder with part of copper powder, and then fully mixing the graphite powder with titanium powder and the rest copper powder to obtain Cu-Ti-graphite mixed powder;
(3) cold press molding: and (3) cold-pressing the Cu-Ti-graphite mixed powder obtained in the step (2) into a cylindrical prefabricated block, wherein the pressure is 80 MPa.
(4) Hot-pressing and sintering: placing the cold-pressed precast block in a hot-pressing sintering furnace for hot-pressing sintering;
the hot-pressing sintering adopts a two-step method: firstly heating to 850 ℃, preserving heat for 60min under the pressure of 100MPa, then further increasing the temperature to 1050 ℃, preserving heat for 1h under the pressure of 600MPa, and finally obtaining the composite material.
The microstructure of the prepared electric contact composite material is shown in figure 1, and the TiC microstructure in the prepared electric contact composite material is shown in figure 2, so that the TiC is connected to form a continuous network.
Through tests, the hardness of the TiC reinforced copper-based electric contact composite material prepared in the embodiment is 215HV, and the electric conductivity is 43% IACS.
Example 2
(1) Preparing raw materials: weighing titanium powder with the granularity of 50 mu m and the purity of more than 99 percent according to the mass percent: 8 percent of graphite powder with the granularity of 5 mu m and the purity of more than 99 percent: 2 percent of copper powder with the granularity of 50 mu m and the purity of more than 99.5 percent;
2) mixing raw materials: firstly, uniformly mixing graphite powder with part of copper powder, and then fully mixing the graphite powder with titanium powder and the rest copper powder to obtain Cu-Ti-graphite mixed powder;
(3) cold press molding: cold-pressing the Cu-Ti-graphite mixed powder obtained in the step (2) into a cylindrical prefabricated block at the pressure of 80 MPa;
(4) hot-pressing and sintering: placing the cold-pressed precast block in a hot-pressing sintering furnace for hot-pressing sintering;
the hot-pressing sintering adopts a two-step method: firstly heating to 850 ℃, preserving heat for 30min under the pressure of 100MPa, then further increasing the temperature to 1050 ℃, preserving heat for 1h under the pressure of 500MPa, and finally obtaining the composite material.
The TiC reinforced copper-based electric contact composite material prepared in the embodiment is tested to have the hardness of 159HV and the electric conductivity of 62% IACS.
Example 3
(1) Preparing raw materials: weighing titanium powder with the granularity of 10 mu m and the purity of more than 99 percent according to the mass percent: 4% of graphite powder with the granularity of 3 mu m and the purity of more than 99%: 1 percent of copper powder with the granularity of 20 mu m and the purity of more than 99.5 percent;
2) mixing raw materials: firstly, uniformly mixing graphite powder with part of copper powder, and then fully mixing the graphite powder with titanium powder and the rest copper powder to obtain Cu-Ti-graphite mixed powder;
(3) cold press molding: cold-pressing the Cu-Ti-graphite mixed powder obtained in the step (2) into a cylindrical prefabricated block under the pressure of 50 MPa;
(4) hot-pressing and sintering: placing the cold-pressed precast block in a hot-pressing sintering furnace for hot-pressing sintering;
the hot-pressing sintering adopts a two-step method: firstly heating to 900 ℃, preserving heat for 30min under the pressure of 100MPa, then further increasing the temperature to 1050 ℃, preserving heat for 1h under the pressure of 300MPa, and finally obtaining the composite material.
Through tests, the hardness of the TiC reinforced copper-based electric contact composite material prepared in the embodiment is 143HV, and the electric conductivity is 75% IACS.
The principles and embodiments of the present invention have been described herein using specific examples, which are provided only to help understand the method and the core concept of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the above, the present disclosure should not be construed as limiting the invention.
Claims (6)
1. The Cu-TiC electric contact composite material is characterized by being prepared from the following raw materials in percentage by mass:
1-10% of graphite powder, 4-40% of titanium powder and the balance of copper powder;
the granularity of the titanium powder is 5-200 mu m, the granularity of the graphite powder is 1-50 mu m, and the granularity of the copper powder is 1-300 mu m;
the TiC in the electric contact composite material forms a continuous network-shaped reinforcement in a network shape.
2. The method of claim 1, comprising the steps of:
(1) preparing raw materials: weighing titanium powder, graphite powder and copper powder according to mass percentage;
(2) mixing raw materials: dividing copper powder into two parts, firstly, uniformly mixing graphite powder and the first part of copper powder in an argon atmosphere, and then fully mixing the graphite powder and the first part of copper powder with titanium powder and the rest copper powder to obtain Cu-Ti-graphite mixed powder;
(3) cold press molding: cold-pressing the Cu-Ti-graphite mixed powder into a cylindrical prefabricated block;
(4) hot-pressing and sintering: and (4) placing the cold-pressed precast block in a vacuum hot-pressing sintering furnace, and performing hot-pressing sintering to obtain the finished composite material.
3. The method for preparing the Cu-TiC electrical contact composite material as claimed in claim 2, wherein in the step (2), the copper powder is divided into two parts, the mass ratio of the first part of copper powder to the graphite is 4-15:1, and the rest is the second part of copper powder.
4. The method for preparing Cu-TiC electric contact composite material as claimed in claim 2, wherein the step (2) is mixing graphite powder with the first part of copper powder for 2-10h under argon atmosphere.
5. The method for preparing Cu-TiC electrical contact composite material according to claim 2, wherein the pressure of cold press molding in the step (3) is 50-100 MPa.
6. The method for preparing Cu-TiC electric contact composite material according to claim 2, wherein the step of vacuum hot pressing sintering in the step (4) is as follows:
1) carrying out hot-pressing sintering on the cold-pressed precast block under the pressure of 100-300MPa, wherein the sintering temperature is 850-950 ℃, and the sintering time is 0.5-2 h;
2) after the step 1) sintering, raising the temperature to 1050-.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN113981263A (en) * | 2021-10-26 | 2022-01-28 | 北京科技大学 | Method for preparing copper-based titanium carbide composite material through in-situ reaction |
| CN114574724A (en) * | 2022-01-20 | 2022-06-03 | 浙江大学温州研究院 | Directionally distributed SnO2/A2Sn2O7Preparation method of complex phase ceramic reinforced silver-based composite material |
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| CN108149059A (en) * | 2018-02-06 | 2018-06-12 | 国网河北能源技术服务有限公司 | A kind of TiC enhances the preparation method of copper-based electric contact composite material |
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