CA1177287A - High density sintered powdered metal alloy and method of producing same - Google Patents
High density sintered powdered metal alloy and method of producing sameInfo
- Publication number
- CA1177287A CA1177287A CA000365197A CA365197A CA1177287A CA 1177287 A CA1177287 A CA 1177287A CA 000365197 A CA000365197 A CA 000365197A CA 365197 A CA365197 A CA 365197A CA 1177287 A CA1177287 A CA 1177287A
- Authority
- CA
- Canada
- Prior art keywords
- article
- alloy
- particles
- sintered
- density
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C33/00—Making ferrous alloys
- C22C33/02—Making ferrous alloys by powder metallurgy
- C22C33/0207—Using a mixture of prealloyed powders or a master alloy
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
- B22F1/09—Mixtures of metallic powders
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Powder Metallurgy (AREA)
Abstract
Abstract of the Disclosure A sintered powdered metal article having a density approaching theoretical is provided by a process which minimizes the amount of fine particles required to obtain satisfactory densification upon sintering. This unique article is produced by a novel process which comprises (a) providing base metal particles having a median particle size greater than 40 microns;
(b) providing alloy forming particles having a median particle size of 20 microns or less, with the alloy forming particles being alloyable with said base metal particles; (c) mixing the alloy forming particles with the base metal particles so as to form a particle mixture capable of being sintered to near theoretical density which mixture contains a minor amount of alloy forming particles; (d) compacting the mixture of alloy forming particles and base metal particles into an article of the desired configuration having a green density sufficient to render the so-produced article capable of being sintered to near theoretical density; and (e) sintering the article at a temperature below that at which any liquid phase is formed in the article to produce a sintered article which has a density approaching that of theoretical.
(b) providing alloy forming particles having a median particle size of 20 microns or less, with the alloy forming particles being alloyable with said base metal particles; (c) mixing the alloy forming particles with the base metal particles so as to form a particle mixture capable of being sintered to near theoretical density which mixture contains a minor amount of alloy forming particles; (d) compacting the mixture of alloy forming particles and base metal particles into an article of the desired configuration having a green density sufficient to render the so-produced article capable of being sintered to near theoretical density; and (e) sintering the article at a temperature below that at which any liquid phase is formed in the article to produce a sintered article which has a density approaching that of theoretical.
Description
1~ 117~Z87 Background _ _ he InventiGn This invention relates to the art of po~der metallurgy and more particularly to the metho~ of ma~ing a high density po~ered metal alloy article and to the products of such method.
For many years, powder metallurgists have been attempt-ing to produce structural powder metal alloys which exhibit a ! high sintered density. To accomplish this, various techniques I have been developed to reduce the porosity of the powder alloys I to a minimum to therebv increase the sintered density of the 10 ¦ concerned article to near theoretical.
¦ For example, it has been known in the prior art to produce high density powdered metal products by the use of secondary processing techniques such as hot or cold working and/or hot isostatic pressing. These secondary operations, however, greatly add to the cost of the finished product and i are to be avoided, if possible.
Ii In addition, it is knot~n in the art to produce rela-¦¦ tively lligh density powdered products by sintering them at a !! temperature which introduces a liquid phase. Much of the 20 ¦¦ recent wor~ in this area has involved introducing a transient liquid phase. ~lowever, the use o~ a liquid phase has the draw-¦i back of introducing many reliability ~ro~lems, esyecially with ¦ regard to brittleness. Add~tionally, the control of the exact sintering temperature becomes very important and in commercial ~ractice is very difficult to main~ain.
Also, it is known in the art to produce relatively high density powdered products bv forming them entirely out of a very ine grain powder. This technique, as evidenced by U.S. Patent 3,744,993, requires extra processing steps to pro-duce the fine powder and to assure that all the pouder is of !¦ the proper size. However, this ~echnique is not withou~ signi-I ficant problems. In this regard, perhaps the most significant ,~ ~
1177;Z8~
problem associated with the technique of using all fin~ po~Jder is that the smaller the particle size of the powder, the greater is its tendency to be pyrophoric. Obviously, it is desirable to avoid or minimize problems associated with the use of such pyrophoric materials.
Accordingly, it is the principal object of the present invention to provide a method of producing a sintered powdered metal alloy article by powder metallurgy techniques which article exhibits a higher degree of aensification than is found in a similar article produced by prior art techniques.
It is another object of the present invention to provide an improved method of producing high density powder metal alloys from powders by means of a single pressing and sintering operation.
lS It is still another object of the present invention to provide an improved sintered powdered metal article having a relatively high density.
A further object of the invention is to provide a powder metallurgy technique for producing a high density sintered metal while reducing the amount of fine particles required to produce the same to thereby minimize the problems typically associated with the handling of pyrophoric materials.
Other objects of the-invention will become apparent from a reading of the following specification and claims.
Summary of the Invention In one aspect, the present invention concerns a process for producing a sintered powdered metal alloy articie composed of a base metal and an alloying metal which article is characterized by having a density near theoretical which method comprises:
(a) providing base metal particles having a median particle size of greater than ~0 microns;
1177;~H7 (b) providing alloy ~orr,ling particles ha~in~ a median partlcle size of 20 microns or less, with the alloy forming particles being allo~able ~Jith said base metal particles;
(c) mixing the al.loy forming particles ~7ith base metal particles so as to form a particle mixture capable of being sintered to near theoretical density which mixture con-tains a minor amount of alloy forming particles;
~d~ compacting the mixture of allo~ forming particles and base metal particles into an article of the desired con-figuration having a ~,reen density sufficient to render the ¦ so-formed article capable of being sintered to near theoretical density; and (e) sintering the article at a temperature below that ¦ at which any liquid phase is formed in said article.
In another aspect, the present invention relates to ¦ a sintered powdered metal alloy article having a density ¦l approaching theoretical which is characterized by having physi-¦¦ cal properties similar to those o~ a wrought metal alloy article I¦ having the same chemical composition which sintered article is ¦I produced by a process which comprises:
I (a) providing base metal. particles having a median ¦ parti~le size of grea~er than ~0 microns;
(b) providing alloy forming particles having a median particle size of 20 microns or less, with the allo~J-forming particles being alloyable with said base metal particles;
(c) mixing the alloy forming particles with base metal particles so as to form a particle mixture capable of- .
¦ being sintered to near theoretica]. density which mixture con-¦ tains a minor amount of alloy forr.ling particles;
~ (d~ compacting the mix~ure of alloy forming particles ¦! and base metal particles into an article of the desired config-1l uration having a green density sufficient to render the '7~ ~ 7 so-forme(l ar~icl~ c~E-ahle of b~in~ sint~r~ to ne~r th~oretical I detlsity; ancl I (c) sintering the article at a t~mperature belo~
¦I that at which any li~uid phase is formed in said article.
ll Br_ef Descrip~ion of the Preferred Practice of the Invention Tlle present invention concerns a novel sintered powder ,¦ metal alloy article and the method of producing the same.
In practice, the article of the invention is produced from at least two special types of powdered metal particles, I specifically alloy forming particles and base metal particles, which particles, in turn, are mixed togetl~er, compacted and then sintered in a manner such that no liquid phase is formed during the sintering procedure. In this regard, as used herein the term "alloy forming particles" includes one or more ll elemental metal particles whic~l combine to form an alloy, articles of a pre-alloyed material and mixtures of such par-ticles. In addition, as used herein the term 'lapproaching"
or "near theoret~cal" densitv is in~e~ded to mean a density ¦I which is higher (greater) than the density of a sirnilar article 1 which is formed by prior art powder metal forming techniques.
, The chemical composition of the ~loy forming particles Il is not cri~ical, except that i~ ~us~ be chemically compatible with the base metal par~icles, that is, it must be alloyable with such particles. In addition, it is thought that the - 25 relative diffusion rates of the alloy forming particles and the base metal particles must be of a relatively comparable magnitude By way of example and not for the purpose of limit-ing the sco~e of the invention, typical of materials used to I form such alloy forming particles or mixing with titanium are ll aluminum-vanadiu~ alloys; alu~inum-vanadium-tin alloys;
and aluminur.-tln-molybdenum-zlrconium alloys, For 117'7Z87 I ~ixin~ with iron, typical ~aterials are elemental silicon, ,I tungsten, molybdenu~, chromiu~, nickel, and vanadium.
To obtain the maximum benefits of the present inven-tion it is essential that the median particle size of the alloy 1¦ forming particles be 20 microns or less. This can be accom-¦ plished via a number of well l~no~m techniques. ~owever, it has been found that such particles can be readily obtained by attriting alloy forming particles in a commerciall~ available l apparatus, such as a Szegvari 1 ~ attri~or; manufactured by ¦ Union Process Inc., Akron, Ohio. In practice, it has been found desirable to utilize alloy forming particles having a median particle size ranging from about 0 5 to 20 microns, with the best results obtained when the particle size range is from ¦ about 2 to about 10 microns.
I The base metal particles used in the practice of the i present invention can be produced by a myrid of well known ¦ techniques and as such techniques do not orm a part of the ¦ present invention they will not be described herein. However, ¦ it is essential to the practice of the invention that the base 1! metal particles utilized have a ~edian particle size by ~eight ¦ of greater than 40 microns, uith good results being realized ¦ when the median particle size by weight of the base metal p~rticles ranges froM about 40 to about 177 microns, and exceptional results being achieved when ~he particle size range by weight is from abou~ 44 to 105 microns.
Typical base metals are titanium, zirconium, iron and nickel. While it is preferred that the base metal particles utilized be chemicall~J pure, as used herein the term "base I metal" particles i5 intended to include elemental metals and ¦ metal alloys wherein the allo~yin~ element or elements are present in minor or trace amounts. Generally speaking, the i 17 ~ ~ 7 the base metal utilized should be commercially pur~ and contain in excess of about 99 we ght percent of the selected metal.
The alloy forming ~articles and the base metal par-ticles can be mixed together in any conventional manner, for example by simple mechanical blending, with the alloy forming I particles being present in an amount sufficient to cause satisfactory densification upon sintering. However, it is essential that the major component of the alloy forming par-ticle-base metal particle mixture be base metal particles. In ¦ practice, if the base metal is titanium, it is preferred that it be present in the resultant mixture in an amount ranging from about 70 weight percent to about 95 weight percent with exceptionally good results being achieved when the amount of base metal ranges from 75 to 92 weight percent. ~hen the base ¦ metal is iron, these ranges are 70 to 98 and 85 to 98, respec-tively.
¦ In mixing the alloy forming par~icles and base metal particles it is essential that the weight ratio of particles ¦ be selec~ed in such a manner that the resultant powder is ¦ capable of being formed and then sintered to near theoretical I density without the formation of any liquid phase. That is, ¦ depending on the specific co~position of the alloy forming ¦ particles, various amounts or ratios of alloy forming particles to base metal particles can be utilized. This can~be deter-¦ mined emperically with the criterion being that (a) the alloy forming particles have a median particle size by weight of ~0 microns or less and (b) that the formed article be compac-tible to a degree sufficient to yield upon sintering an article having a density which is near theoretical.
I In forming the article of the invention no special ¦¦ procedures are required, exce~t tha~ the article must be com-pacted to a degree sufficient to render the resultant article ¦ capable of being sinterecl to near theoretical ~ensity. Both Il conventional and isostatic molding techniques have been ¦l employed successfully. In practice, it has been found satis-~ factory to fonm or compact the green article to a density of I about 65 to about 90 percent of theoretical with excellent ¦ results being achieved when the green density ranges from about 80 to about 90 percent of theoretical.
Once the desired articl~ is formed it can be sintered in a conventional manner. The e.cact sintering temperature employed will vary somewhat depending on thé composition and amount of the various components which make up the article, with the only requirement being that no liquid phase be formed ¦ during the sintering procedure.
¦ Typical physical properties of articles produced ¦ according to the present invention using titanium as the base ¦¦ metal material are: 135 ksi U.T.S., 125 ksi Y.S., 15% elonga-tion, and 27% RoA~ (the product of Example II).
By way of contrast, the minimum properties specified for a forged, wrought article, as set forth in ASTM B348, ¦ having a similar chemical composition are as follows 130 ~si U.T.S., 120 ksi Y.S., 10% elongation, and 25% R.A.
The subject invention will now be described with ¦¦ reference to the follo~ing examples which are set forth for I the purpose of illustrating the present invention and not for 25 ~ the purpose of limiting the same Examp'e I
Consistent with prior art practice, a 3.7" by 0.58"
by 0060" sintered 90 titanium-6 aluminum-4 vanadium alloy article was obtained as follows.
I Approximately 10 weight percent of a nominal 60 Al/
¦ 40 V alloy powder, -~0 mesh, was blended with 90 ~eight percent -100 mesh Ti. This blend was then cGmpacted at 50 tsi in a ~1~77~87 rigid mold to a green density of about 88-90% of theoretical, and the so-formed article was then vacuum sintered 4 hours at 2300F I 25 to a final density of about 94.5-96 5% of theore-tical. This article exhibited the following physical properties:
115 ksi U.T.S., 108 ksi Y.S., 6% elongation, and 9% ~.A.
Example II
Two pounds of 60 Al/40 V were put into a Szegvari S-l attritor along with about 40 pounds of 1/8" steel balls and about 1/2 gallon of Freon ~trade mark for a fluorocarbon includ-ing trichlorotrifluoroethane~. This Al/V alloy was attrited for 30 minutes, removed from the attritor and dried. The resultant median particle siæe, as determined by Coulter counter, was about 3.0 microns. This powder was added to -100 mesh Ti, and processed and sintered as in Example I. The resultant sintered density was 99.3-99.8% of theoretical.
Example III
The procedure of Example II was repeated, except attrition time was 7 minutes with resulting median particle size being approximately 10 microns. The resultant sintered density was 99.0% of theoretical.
Example IV
The procedure of Example II was repeated, except 8 pounds of powder were attrited to a resultant median particle size of about 6.5 microns. The resultant sintered density was 99.5% of theoretical.
Example V
The procedure of Example II was repeated, except dis-tilled H20 was used instead of Freon in the attritor. The resultant sintered density was 99.5-99.8% of theoretical.
Example VI
The procedure of Example II was repeated, except sintering was at 2200F + 30F. The resultant sintered density was 99.3-99.4% of theoretical.
~177'Z87 Example VII
The procedure of Example II was repeated, except the compaction pressure was about 30 tsi. The green density was 83-84% of theoretical. The sintered density ~as 99.0-99.1%
of theoretical.
Example VIII
The procedure of Example II was repeated, except mullite balls were used, with the resultant median particle size being less than 10 microns. The sintered density was 99.5% of theoretical.
Example IX
The procedure of Example II was repeated, except -60 +200 mesh Ti was used. The resultant sintered density was 99.4% of theoretical.
Example X
The procedure of Example I was repeated, except the powder was compacted at 60,000 psi in a flexible mold in an isostatic press to form a 3" diameter billet with a green density of about 86-88% of theoretical. After sintering; the billet had a density of 88-92% of theoretical.
Example XI
The procedure of Example X was repeated, except Al/V
powder prepared as in Example II was used. The resultant sintered density of the 3" billet was 99. 8% of theoretical.
Example XII
A mixture of -325 mesh 50 Al/50 V alloy, -325 mesh Sn, and -100 mesh Ti was formed to give a 86 Ti-6 Al-6 V-2 Sn alloy powder. This mixture was processed as in Example I with the resultant sintered density being about 96.6% of theoretical.
The physical properties of this article were: 131 ksi U.T.S., 113 ksi Y.S., 6% elongation, and 10% R.A.
:~177~87 EX~PLE XIII
An alloy of 42 Al-42 V-16 Sn was attrited as des-cribed in Example II. Subse~uently, this attrited mixture was mixed with -100 mesh Ti and processed as described in Example I to produce a composition 86 Ti - 6 Al - 6 V - 2 Sn alloy. The resultant sintered density was approximately 99.0/O
of theoretical. The physical properties of this article were:
152 ksi U.T.S., 13~ ksi Y.S., 9% elongation and 16.7% R.A.
Illustrating the present invention with respect to iron base sintered articles produced according to the present invention are the following Examples XIV through XXII.
EXAMPLE XIV
Elemental silicon powder having a medium particle size by weight of about 60 microns was blended with atomized iron (-80 mesh Ancor* steel lOOOB, a standard steel powder com-prising 99.2% Fe, 0.105% C, 0 018% S, 0.01% Pb and 0.22% Mn) so as to obtain a resultant mixture of about 3 weight percent silicon, with the remainder being iron. This mixture was formed into the desired configuration and compacted at 50 tsi.
The so-formed had a green density o~ 6.6 g/cc. It was then sintered for 2 hours at 2175F (in hydrogen). The resultant sintered density was 6.94 g/cc, which is about 90.7% of theoretical.
EXAMPLE XV
The procedure of Example XIVWas repeated, except the silicon was attrited to a median particle size of 4 microns.
The green density of the article was 6.69 g/cc. The resultant sintered density was 7.4 g/cc, which is 96.7% of theoretical.
EXAMPLE XVI
The procedure of Example XV was repeated, except sufficient silicon was added to produce a mixture containing 5% silicon. The green density of the article was 6.29 g/cc.
The resultant sintered density was 7.17 g/cc, which is 95.0/O
of theoretical.
* trade mark 1177~7 F.XAMPLF XVII
A ferrosilicon alloy (approximately 50% Fe-50~ Si) was attrited about 30 minutes in Freon to a median particle size, by weight, of about 2 microns. This material ~as then added to iron ~Or the type described in Example XVI) in an amount suffl-cient to produce a mixture containing 2% silicon, balance iron.
It was compacted to a gIeen density of 7 . o6 g/cc and then sintered for 30 minutes at 2050F in hydrogen. The resultant sintered density was 7 . 3 g/cc, which is 94.5% of theoretical.
EXAMPLE XVIII
Elemental molybdenum having a median particle size of 9 microns was mixed with iron (of the type described in Example XIV) to produce three Fe-Mo blends containing, respec-tively, 1, 5 and 10% Mo. After compacting to a green density f 7 25g/cc 7.32 g/cc and 7.38 g/cc, respectively, and sintering for 4 hours at 2300F in hydrogen, the Fe-1% Mo articles exhibited a density of 7.28 g/cc, the Fe-5% Mo article a density of 7.72 g~cc, and the Fe-10% Mo article a density of 7.78 gJcc. These sintered densities are about 92.3, 96.8 and 96.3% of theoretical,respectively.
EXHIBIT XIX
The procedure of Example XVIII was repeated, except chromium having a median particle size of 5.6 microns was added to iron to produce articles containing Fe-5% Cr, Fe-10% Cr, and and Fe-15% Cr. The Fe-5Cr article had a green density of about 7.14 g/cc and a sintered density of about 7.15 gfcc. The Fe-10 Cr article had a green density of 6.93 g/cc and a sintered density Or 7.38 g/cc.
The Fe-15% Cr article had a green density Or 6.75 g/cc and a sin-tered density of 7.30 g/cc. These sintered densities are 91.3, 94.7 and 94.4% of theoretical, respectively.
1177~87 Example XX
The procedure of Example XIX was repeated, except -100 mesh electrolytic chromium was used. The Fe-lOCr article had a green density o~ 6.98 g/cc and a sintered density of 7.1 g/cc. The Fe-15% Cr had a green density of 6.90 g/cc and a sintered density of 6.96 g/cc. These sintered densities are 91.1 and 89.7% of theoretical, respectively.
Example XXI
Inco 287 (material designation for a standard nickel powder of International ~ickel) nickel powder (5-10 micron particle size) was blended with iron powder (of the type described in Example XIV) to produce a mixture containing 10%
~i. This mixture was compacted to a green density of 7.21 g/cc and then sintered at 2300F for 4 hours in vacuum. The sintered density was 7.49 g/cc. This density is 94% of theoretical.
- Example XXII
The procedure of Example XXI was repeated, except -200 +325 mesh nickel was used. The green density was 7.21 g/cc. There was essentially no change in density after sinter-ing. This sintered density is 90.5% of theoretical.
The following Examples concern the use of zirconium and nickel as base metals.
Example XXIII
A 60 Al/40 V alloy material was attrited for 30 minutes in Freon to a median particle size of 3 microns. This material was then blended with -100 mesh zirconium to produce a mixture containing, by weight, 90/0 zirconium, 6% aluminum and 4% vanadium which mixture, in turn, was formed into the desired shape and sintered at 2200F for 4 hours under vacuum conditions (better than 1 micron). The green density was 4.58 g/cc with the sintered density being 5.90 g~cc, which is 98.8% of theoretical density.
1177~7 EX~PLF X~IV
A nickel-alumlnum (approximately 67% Ni - 33% Al) mater~al was attrited to a median particle size of 3.0 microns. Thls ~Jas added to -80 ~325 mesh nickel powder to produce a mixture containing 95.5 Ni-4.5 Al. The green article formed therefrom had a density of 6.4 g/cc. After sintering at 2300F for 4 hours under vacuum conditions, the resultant article had a density of about 7.1 g/cc.
EXAMPLE XXV
.
The procedure of Example XXIV was repeated, except sufficient aluminum was added to produce a mixture which con-tained 92.5~ Ni and 7.5% Al. The green density was 5.5 g/cc, the sintered density was 6.5 g/cc.
The benefits of the present invention are apparent from the foregoing illustrative Examples. For example, it is to be noted that a conventionally produced powdered metal 90 T~- 6 Al- 4 V
alloy had a density of 94.5-96.5~ of theoretical (Example I) whereas an essentially identical 90 Ti - 6 Al - 4 V alloy produced by the technique of the present invention had a density of 99.3-99.8%
of theoretical (Example II). This dirference in percent of theoreti-cal density is exceptionally significant because the article having a density of 99.3-99.8% of theoretical exhibits chemical and physical properties similar to a wrought alloy of the same composition whereas the article having a density which was 94.5-g6.5% of theoretical does not.
It should be noted that the particle sizes set forth herein were determined by use of a Coulter counter and that the particle size given is the median particle size by weight deter-mined by the use of this apparatus.
Titanium base articles produced according to the present invention are characterized by the fact that they can contain relatively high amounts Or oxygen (up to about 0.30-0.35 weight pe~cent) and still exhibit excellent ductility (an ~13-elongation of about 12~13 percent). Ihis is in contradistinc-tion to cast or wrought articles of a si~ilar chemical composi-¦ tion (having an oxygen content ranging from about C.30 to about 0.35 percent) which exhibit limited ductility (an elon~ation o~
1 about 5-6 percent) That is, titanium base articles produced ¦ according to the present invention get strength from the presence of relatively high amounts of oxygen, but this does not destroy their ductility. Such articles are obviously superior to those produced by ~rior art techniques.
In the practice of the invention, it is preferred to adjust the process para~eters such that the resultant sintered density of the concerned powdered metal article is greater ¦ than about 97% of theoretical when the base metal particles are ¦ titanium and greater tllan about 93~o of theoretical when such 15 ¦¦ base metal particles are iron.
~ Jhile there have been described what are at present considered to be the preferred embodiments of this invention, ! it will be obvious to those skilled in the art that various ¦ changes and ~odifications may be made therein without depart-¦ ing from the invention, and it is~ therefore, aimed in the appended claims to cover all such changes and modifications as fall with~n the true spirit snd scope of the invention.
For many years, powder metallurgists have been attempt-ing to produce structural powder metal alloys which exhibit a ! high sintered density. To accomplish this, various techniques I have been developed to reduce the porosity of the powder alloys I to a minimum to therebv increase the sintered density of the 10 ¦ concerned article to near theoretical.
¦ For example, it has been known in the prior art to produce high density powdered metal products by the use of secondary processing techniques such as hot or cold working and/or hot isostatic pressing. These secondary operations, however, greatly add to the cost of the finished product and i are to be avoided, if possible.
Ii In addition, it is knot~n in the art to produce rela-¦¦ tively lligh density powdered products by sintering them at a !! temperature which introduces a liquid phase. Much of the 20 ¦¦ recent wor~ in this area has involved introducing a transient liquid phase. ~lowever, the use o~ a liquid phase has the draw-¦i back of introducing many reliability ~ro~lems, esyecially with ¦ regard to brittleness. Add~tionally, the control of the exact sintering temperature becomes very important and in commercial ~ractice is very difficult to main~ain.
Also, it is known in the art to produce relatively high density powdered products bv forming them entirely out of a very ine grain powder. This technique, as evidenced by U.S. Patent 3,744,993, requires extra processing steps to pro-duce the fine powder and to assure that all the pouder is of !¦ the proper size. However, this ~echnique is not withou~ signi-I ficant problems. In this regard, perhaps the most significant ,~ ~
1177;Z8~
problem associated with the technique of using all fin~ po~Jder is that the smaller the particle size of the powder, the greater is its tendency to be pyrophoric. Obviously, it is desirable to avoid or minimize problems associated with the use of such pyrophoric materials.
Accordingly, it is the principal object of the present invention to provide a method of producing a sintered powdered metal alloy article by powder metallurgy techniques which article exhibits a higher degree of aensification than is found in a similar article produced by prior art techniques.
It is another object of the present invention to provide an improved method of producing high density powder metal alloys from powders by means of a single pressing and sintering operation.
lS It is still another object of the present invention to provide an improved sintered powdered metal article having a relatively high density.
A further object of the invention is to provide a powder metallurgy technique for producing a high density sintered metal while reducing the amount of fine particles required to produce the same to thereby minimize the problems typically associated with the handling of pyrophoric materials.
Other objects of the-invention will become apparent from a reading of the following specification and claims.
Summary of the Invention In one aspect, the present invention concerns a process for producing a sintered powdered metal alloy articie composed of a base metal and an alloying metal which article is characterized by having a density near theoretical which method comprises:
(a) providing base metal particles having a median particle size of greater than ~0 microns;
1177;~H7 (b) providing alloy ~orr,ling particles ha~in~ a median partlcle size of 20 microns or less, with the alloy forming particles being allo~able ~Jith said base metal particles;
(c) mixing the al.loy forming particles ~7ith base metal particles so as to form a particle mixture capable of being sintered to near theoretical density which mixture con-tains a minor amount of alloy forming particles;
~d~ compacting the mixture of allo~ forming particles and base metal particles into an article of the desired con-figuration having a ~,reen density sufficient to render the ¦ so-formed article capable of being sintered to near theoretical density; and (e) sintering the article at a temperature below that ¦ at which any liquid phase is formed in said article.
In another aspect, the present invention relates to ¦ a sintered powdered metal alloy article having a density ¦l approaching theoretical which is characterized by having physi-¦¦ cal properties similar to those o~ a wrought metal alloy article I¦ having the same chemical composition which sintered article is ¦I produced by a process which comprises:
I (a) providing base metal. particles having a median ¦ parti~le size of grea~er than ~0 microns;
(b) providing alloy forming particles having a median particle size of 20 microns or less, with the allo~J-forming particles being alloyable with said base metal particles;
(c) mixing the alloy forming particles with base metal particles so as to form a particle mixture capable of- .
¦ being sintered to near theoretica]. density which mixture con-¦ tains a minor amount of alloy forr.ling particles;
~ (d~ compacting the mix~ure of alloy forming particles ¦! and base metal particles into an article of the desired config-1l uration having a green density sufficient to render the '7~ ~ 7 so-forme(l ar~icl~ c~E-ahle of b~in~ sint~r~ to ne~r th~oretical I detlsity; ancl I (c) sintering the article at a t~mperature belo~
¦I that at which any li~uid phase is formed in said article.
ll Br_ef Descrip~ion of the Preferred Practice of the Invention Tlle present invention concerns a novel sintered powder ,¦ metal alloy article and the method of producing the same.
In practice, the article of the invention is produced from at least two special types of powdered metal particles, I specifically alloy forming particles and base metal particles, which particles, in turn, are mixed togetl~er, compacted and then sintered in a manner such that no liquid phase is formed during the sintering procedure. In this regard, as used herein the term "alloy forming particles" includes one or more ll elemental metal particles whic~l combine to form an alloy, articles of a pre-alloyed material and mixtures of such par-ticles. In addition, as used herein the term 'lapproaching"
or "near theoret~cal" densitv is in~e~ded to mean a density ¦I which is higher (greater) than the density of a sirnilar article 1 which is formed by prior art powder metal forming techniques.
, The chemical composition of the ~loy forming particles Il is not cri~ical, except that i~ ~us~ be chemically compatible with the base metal par~icles, that is, it must be alloyable with such particles. In addition, it is thought that the - 25 relative diffusion rates of the alloy forming particles and the base metal particles must be of a relatively comparable magnitude By way of example and not for the purpose of limit-ing the sco~e of the invention, typical of materials used to I form such alloy forming particles or mixing with titanium are ll aluminum-vanadiu~ alloys; alu~inum-vanadium-tin alloys;
and aluminur.-tln-molybdenum-zlrconium alloys, For 117'7Z87 I ~ixin~ with iron, typical ~aterials are elemental silicon, ,I tungsten, molybdenu~, chromiu~, nickel, and vanadium.
To obtain the maximum benefits of the present inven-tion it is essential that the median particle size of the alloy 1¦ forming particles be 20 microns or less. This can be accom-¦ plished via a number of well l~no~m techniques. ~owever, it has been found that such particles can be readily obtained by attriting alloy forming particles in a commerciall~ available l apparatus, such as a Szegvari 1 ~ attri~or; manufactured by ¦ Union Process Inc., Akron, Ohio. In practice, it has been found desirable to utilize alloy forming particles having a median particle size ranging from about 0 5 to 20 microns, with the best results obtained when the particle size range is from ¦ about 2 to about 10 microns.
I The base metal particles used in the practice of the i present invention can be produced by a myrid of well known ¦ techniques and as such techniques do not orm a part of the ¦ present invention they will not be described herein. However, ¦ it is essential to the practice of the invention that the base 1! metal particles utilized have a ~edian particle size by ~eight ¦ of greater than 40 microns, uith good results being realized ¦ when the median particle size by weight of the base metal p~rticles ranges froM about 40 to about 177 microns, and exceptional results being achieved when ~he particle size range by weight is from abou~ 44 to 105 microns.
Typical base metals are titanium, zirconium, iron and nickel. While it is preferred that the base metal particles utilized be chemicall~J pure, as used herein the term "base I metal" particles i5 intended to include elemental metals and ¦ metal alloys wherein the allo~yin~ element or elements are present in minor or trace amounts. Generally speaking, the i 17 ~ ~ 7 the base metal utilized should be commercially pur~ and contain in excess of about 99 we ght percent of the selected metal.
The alloy forming ~articles and the base metal par-ticles can be mixed together in any conventional manner, for example by simple mechanical blending, with the alloy forming I particles being present in an amount sufficient to cause satisfactory densification upon sintering. However, it is essential that the major component of the alloy forming par-ticle-base metal particle mixture be base metal particles. In ¦ practice, if the base metal is titanium, it is preferred that it be present in the resultant mixture in an amount ranging from about 70 weight percent to about 95 weight percent with exceptionally good results being achieved when the amount of base metal ranges from 75 to 92 weight percent. ~hen the base ¦ metal is iron, these ranges are 70 to 98 and 85 to 98, respec-tively.
¦ In mixing the alloy forming par~icles and base metal particles it is essential that the weight ratio of particles ¦ be selec~ed in such a manner that the resultant powder is ¦ capable of being formed and then sintered to near theoretical I density without the formation of any liquid phase. That is, ¦ depending on the specific co~position of the alloy forming ¦ particles, various amounts or ratios of alloy forming particles to base metal particles can be utilized. This can~be deter-¦ mined emperically with the criterion being that (a) the alloy forming particles have a median particle size by weight of ~0 microns or less and (b) that the formed article be compac-tible to a degree sufficient to yield upon sintering an article having a density which is near theoretical.
I In forming the article of the invention no special ¦¦ procedures are required, exce~t tha~ the article must be com-pacted to a degree sufficient to render the resultant article ¦ capable of being sinterecl to near theoretical ~ensity. Both Il conventional and isostatic molding techniques have been ¦l employed successfully. In practice, it has been found satis-~ factory to fonm or compact the green article to a density of I about 65 to about 90 percent of theoretical with excellent ¦ results being achieved when the green density ranges from about 80 to about 90 percent of theoretical.
Once the desired articl~ is formed it can be sintered in a conventional manner. The e.cact sintering temperature employed will vary somewhat depending on thé composition and amount of the various components which make up the article, with the only requirement being that no liquid phase be formed ¦ during the sintering procedure.
¦ Typical physical properties of articles produced ¦ according to the present invention using titanium as the base ¦¦ metal material are: 135 ksi U.T.S., 125 ksi Y.S., 15% elonga-tion, and 27% RoA~ (the product of Example II).
By way of contrast, the minimum properties specified for a forged, wrought article, as set forth in ASTM B348, ¦ having a similar chemical composition are as follows 130 ~si U.T.S., 120 ksi Y.S., 10% elongation, and 25% R.A.
The subject invention will now be described with ¦¦ reference to the follo~ing examples which are set forth for I the purpose of illustrating the present invention and not for 25 ~ the purpose of limiting the same Examp'e I
Consistent with prior art practice, a 3.7" by 0.58"
by 0060" sintered 90 titanium-6 aluminum-4 vanadium alloy article was obtained as follows.
I Approximately 10 weight percent of a nominal 60 Al/
¦ 40 V alloy powder, -~0 mesh, was blended with 90 ~eight percent -100 mesh Ti. This blend was then cGmpacted at 50 tsi in a ~1~77~87 rigid mold to a green density of about 88-90% of theoretical, and the so-formed article was then vacuum sintered 4 hours at 2300F I 25 to a final density of about 94.5-96 5% of theore-tical. This article exhibited the following physical properties:
115 ksi U.T.S., 108 ksi Y.S., 6% elongation, and 9% ~.A.
Example II
Two pounds of 60 Al/40 V were put into a Szegvari S-l attritor along with about 40 pounds of 1/8" steel balls and about 1/2 gallon of Freon ~trade mark for a fluorocarbon includ-ing trichlorotrifluoroethane~. This Al/V alloy was attrited for 30 minutes, removed from the attritor and dried. The resultant median particle siæe, as determined by Coulter counter, was about 3.0 microns. This powder was added to -100 mesh Ti, and processed and sintered as in Example I. The resultant sintered density was 99.3-99.8% of theoretical.
Example III
The procedure of Example II was repeated, except attrition time was 7 minutes with resulting median particle size being approximately 10 microns. The resultant sintered density was 99.0% of theoretical.
Example IV
The procedure of Example II was repeated, except 8 pounds of powder were attrited to a resultant median particle size of about 6.5 microns. The resultant sintered density was 99.5% of theoretical.
Example V
The procedure of Example II was repeated, except dis-tilled H20 was used instead of Freon in the attritor. The resultant sintered density was 99.5-99.8% of theoretical.
Example VI
The procedure of Example II was repeated, except sintering was at 2200F + 30F. The resultant sintered density was 99.3-99.4% of theoretical.
~177'Z87 Example VII
The procedure of Example II was repeated, except the compaction pressure was about 30 tsi. The green density was 83-84% of theoretical. The sintered density ~as 99.0-99.1%
of theoretical.
Example VIII
The procedure of Example II was repeated, except mullite balls were used, with the resultant median particle size being less than 10 microns. The sintered density was 99.5% of theoretical.
Example IX
The procedure of Example II was repeated, except -60 +200 mesh Ti was used. The resultant sintered density was 99.4% of theoretical.
Example X
The procedure of Example I was repeated, except the powder was compacted at 60,000 psi in a flexible mold in an isostatic press to form a 3" diameter billet with a green density of about 86-88% of theoretical. After sintering; the billet had a density of 88-92% of theoretical.
Example XI
The procedure of Example X was repeated, except Al/V
powder prepared as in Example II was used. The resultant sintered density of the 3" billet was 99. 8% of theoretical.
Example XII
A mixture of -325 mesh 50 Al/50 V alloy, -325 mesh Sn, and -100 mesh Ti was formed to give a 86 Ti-6 Al-6 V-2 Sn alloy powder. This mixture was processed as in Example I with the resultant sintered density being about 96.6% of theoretical.
The physical properties of this article were: 131 ksi U.T.S., 113 ksi Y.S., 6% elongation, and 10% R.A.
:~177~87 EX~PLE XIII
An alloy of 42 Al-42 V-16 Sn was attrited as des-cribed in Example II. Subse~uently, this attrited mixture was mixed with -100 mesh Ti and processed as described in Example I to produce a composition 86 Ti - 6 Al - 6 V - 2 Sn alloy. The resultant sintered density was approximately 99.0/O
of theoretical. The physical properties of this article were:
152 ksi U.T.S., 13~ ksi Y.S., 9% elongation and 16.7% R.A.
Illustrating the present invention with respect to iron base sintered articles produced according to the present invention are the following Examples XIV through XXII.
EXAMPLE XIV
Elemental silicon powder having a medium particle size by weight of about 60 microns was blended with atomized iron (-80 mesh Ancor* steel lOOOB, a standard steel powder com-prising 99.2% Fe, 0.105% C, 0 018% S, 0.01% Pb and 0.22% Mn) so as to obtain a resultant mixture of about 3 weight percent silicon, with the remainder being iron. This mixture was formed into the desired configuration and compacted at 50 tsi.
The so-formed had a green density o~ 6.6 g/cc. It was then sintered for 2 hours at 2175F (in hydrogen). The resultant sintered density was 6.94 g/cc, which is about 90.7% of theoretical.
EXAMPLE XV
The procedure of Example XIVWas repeated, except the silicon was attrited to a median particle size of 4 microns.
The green density of the article was 6.69 g/cc. The resultant sintered density was 7.4 g/cc, which is 96.7% of theoretical.
EXAMPLE XVI
The procedure of Example XV was repeated, except sufficient silicon was added to produce a mixture containing 5% silicon. The green density of the article was 6.29 g/cc.
The resultant sintered density was 7.17 g/cc, which is 95.0/O
of theoretical.
* trade mark 1177~7 F.XAMPLF XVII
A ferrosilicon alloy (approximately 50% Fe-50~ Si) was attrited about 30 minutes in Freon to a median particle size, by weight, of about 2 microns. This material ~as then added to iron ~Or the type described in Example XVI) in an amount suffl-cient to produce a mixture containing 2% silicon, balance iron.
It was compacted to a gIeen density of 7 . o6 g/cc and then sintered for 30 minutes at 2050F in hydrogen. The resultant sintered density was 7 . 3 g/cc, which is 94.5% of theoretical.
EXAMPLE XVIII
Elemental molybdenum having a median particle size of 9 microns was mixed with iron (of the type described in Example XIV) to produce three Fe-Mo blends containing, respec-tively, 1, 5 and 10% Mo. After compacting to a green density f 7 25g/cc 7.32 g/cc and 7.38 g/cc, respectively, and sintering for 4 hours at 2300F in hydrogen, the Fe-1% Mo articles exhibited a density of 7.28 g/cc, the Fe-5% Mo article a density of 7.72 g~cc, and the Fe-10% Mo article a density of 7.78 gJcc. These sintered densities are about 92.3, 96.8 and 96.3% of theoretical,respectively.
EXHIBIT XIX
The procedure of Example XVIII was repeated, except chromium having a median particle size of 5.6 microns was added to iron to produce articles containing Fe-5% Cr, Fe-10% Cr, and and Fe-15% Cr. The Fe-5Cr article had a green density of about 7.14 g/cc and a sintered density of about 7.15 gfcc. The Fe-10 Cr article had a green density of 6.93 g/cc and a sintered density Or 7.38 g/cc.
The Fe-15% Cr article had a green density Or 6.75 g/cc and a sin-tered density of 7.30 g/cc. These sintered densities are 91.3, 94.7 and 94.4% of theoretical, respectively.
1177~87 Example XX
The procedure of Example XIX was repeated, except -100 mesh electrolytic chromium was used. The Fe-lOCr article had a green density o~ 6.98 g/cc and a sintered density of 7.1 g/cc. The Fe-15% Cr had a green density of 6.90 g/cc and a sintered density of 6.96 g/cc. These sintered densities are 91.1 and 89.7% of theoretical, respectively.
Example XXI
Inco 287 (material designation for a standard nickel powder of International ~ickel) nickel powder (5-10 micron particle size) was blended with iron powder (of the type described in Example XIV) to produce a mixture containing 10%
~i. This mixture was compacted to a green density of 7.21 g/cc and then sintered at 2300F for 4 hours in vacuum. The sintered density was 7.49 g/cc. This density is 94% of theoretical.
- Example XXII
The procedure of Example XXI was repeated, except -200 +325 mesh nickel was used. The green density was 7.21 g/cc. There was essentially no change in density after sinter-ing. This sintered density is 90.5% of theoretical.
The following Examples concern the use of zirconium and nickel as base metals.
Example XXIII
A 60 Al/40 V alloy material was attrited for 30 minutes in Freon to a median particle size of 3 microns. This material was then blended with -100 mesh zirconium to produce a mixture containing, by weight, 90/0 zirconium, 6% aluminum and 4% vanadium which mixture, in turn, was formed into the desired shape and sintered at 2200F for 4 hours under vacuum conditions (better than 1 micron). The green density was 4.58 g/cc with the sintered density being 5.90 g~cc, which is 98.8% of theoretical density.
1177~7 EX~PLF X~IV
A nickel-alumlnum (approximately 67% Ni - 33% Al) mater~al was attrited to a median particle size of 3.0 microns. Thls ~Jas added to -80 ~325 mesh nickel powder to produce a mixture containing 95.5 Ni-4.5 Al. The green article formed therefrom had a density of 6.4 g/cc. After sintering at 2300F for 4 hours under vacuum conditions, the resultant article had a density of about 7.1 g/cc.
EXAMPLE XXV
.
The procedure of Example XXIV was repeated, except sufficient aluminum was added to produce a mixture which con-tained 92.5~ Ni and 7.5% Al. The green density was 5.5 g/cc, the sintered density was 6.5 g/cc.
The benefits of the present invention are apparent from the foregoing illustrative Examples. For example, it is to be noted that a conventionally produced powdered metal 90 T~- 6 Al- 4 V
alloy had a density of 94.5-96.5~ of theoretical (Example I) whereas an essentially identical 90 Ti - 6 Al - 4 V alloy produced by the technique of the present invention had a density of 99.3-99.8%
of theoretical (Example II). This dirference in percent of theoreti-cal density is exceptionally significant because the article having a density of 99.3-99.8% of theoretical exhibits chemical and physical properties similar to a wrought alloy of the same composition whereas the article having a density which was 94.5-g6.5% of theoretical does not.
It should be noted that the particle sizes set forth herein were determined by use of a Coulter counter and that the particle size given is the median particle size by weight deter-mined by the use of this apparatus.
Titanium base articles produced according to the present invention are characterized by the fact that they can contain relatively high amounts Or oxygen (up to about 0.30-0.35 weight pe~cent) and still exhibit excellent ductility (an ~13-elongation of about 12~13 percent). Ihis is in contradistinc-tion to cast or wrought articles of a si~ilar chemical composi-¦ tion (having an oxygen content ranging from about C.30 to about 0.35 percent) which exhibit limited ductility (an elon~ation o~
1 about 5-6 percent) That is, titanium base articles produced ¦ according to the present invention get strength from the presence of relatively high amounts of oxygen, but this does not destroy their ductility. Such articles are obviously superior to those produced by ~rior art techniques.
In the practice of the invention, it is preferred to adjust the process para~eters such that the resultant sintered density of the concerned powdered metal article is greater ¦ than about 97% of theoretical when the base metal particles are ¦ titanium and greater tllan about 93~o of theoretical when such 15 ¦¦ base metal particles are iron.
~ Jhile there have been described what are at present considered to be the preferred embodiments of this invention, ! it will be obvious to those skilled in the art that various ¦ changes and ~odifications may be made therein without depart-¦ ing from the invention, and it is~ therefore, aimed in the appended claims to cover all such changes and modifications as fall with~n the true spirit snd scope of the invention.
Claims (20)
1. A process for producing a sintered, powdered metal alloy article comprised of a base metal and an alloying metal, wherein the article is characterized by having a density near theoretical while minimizing the amount of fine particles required to obtain satisfactory densifi-cation which method comprises:
(a) providing base-metal particles having an average particle size ranging from about 40 to 177 microns;
(b) providing alloy-forming particles having an average particle size ranging from about 0.5 to 20 microns capable of alloying with said base-metal particles;
(c) mixing the alloy-forming particles with at least about 70 weight percent of base-metal particles so as to form a powder mixture capable of being sintered following compaction to near theoretical density, substantially the balance of said mixture being said alloy-forming particles;
(d) compacting the powder mixture into an article of the desired configuration having a green density ranging from about 70 to 90 percent of theoretical density sufficient to render the so-formed article capable of being sintered to near theoretical density;
and (e) sintering the article at an elevated temperature below that at which any liquid phase is formed in said article to produce a sintered, powdered metal alloy article with a near theoretical density.
(a) providing base-metal particles having an average particle size ranging from about 40 to 177 microns;
(b) providing alloy-forming particles having an average particle size ranging from about 0.5 to 20 microns capable of alloying with said base-metal particles;
(c) mixing the alloy-forming particles with at least about 70 weight percent of base-metal particles so as to form a powder mixture capable of being sintered following compaction to near theoretical density, substantially the balance of said mixture being said alloy-forming particles;
(d) compacting the powder mixture into an article of the desired configuration having a green density ranging from about 70 to 90 percent of theoretical density sufficient to render the so-formed article capable of being sintered to near theoretical density;
and (e) sintering the article at an elevated temperature below that at which any liquid phase is formed in said article to produce a sintered, powdered metal alloy article with a near theoretical density.
2. The process of claim 1, wherein said base-metal particles are selected from the group consisting of titanium, iron, zirconium, nickel and alloys of such metals.
3. The process of claim 1, wherein said alloy-forming particles are pre-alloyed articles.
4. The process of claim 3, wherein said pre-alloyed particles are comprised of an alloy of iron and silicon.
5. The process of claim 3, wherein said pre-alloyed particles are comprised of an alloy of vanadium and aluminum.
6. The process of claim 3, wherein said alloy-forming particles are selected from the group consisting of silicon, molybdenum, tungsten, chromium, nickel, vanadium and mixtures thereof.
7. The process of claim 1, wherein the alloy-forming particles are provided with said average particle size of about 0.5 to 20 microns by milling a charge of said alloy-forming particles.
8. The process of claim 7, wherein said milling is done with a liquid and said liquid is a fluorocarbon.
9. The process of claim 8, wherein said fluorocarbon is trichlorotrifluoroethane.
10. The process of claim 7, wherein said milling is done with a liquid and said liquid is Freon.
11. A sintered powdered metal alloy article having a density approaching theoretical which is produced by a process comprising:
(a) providing base-metal particles having an average particle size ranging from about 40 to 177 microns, (b) providing alloy-forming particles having an average particle size ranging from about 0.5 to 20 microns capable of alloy-ing with said base-metal particles, (c) mixing the alloy-forming particles with at least about 70 weight percent of said base-metal particles so as to form a powder mixture capable of being sintered following compaction to near theoretical density, sub-stantially the balance of said mixture being said alloy-forming particles;
(d) compacting the powder mixture into an article of the desired configuration having a green density ranging from about 70 to 90 percent of theoretical density sufficient to render the so-formed article capable of being sintered to near theoretical density; and (e) sintering the article at an elevated temperature below that at which any liquid phase is formed in said article to produce a sintered, powdered metal alloy article having a density approaching theoretical.
(a) providing base-metal particles having an average particle size ranging from about 40 to 177 microns, (b) providing alloy-forming particles having an average particle size ranging from about 0.5 to 20 microns capable of alloy-ing with said base-metal particles, (c) mixing the alloy-forming particles with at least about 70 weight percent of said base-metal particles so as to form a powder mixture capable of being sintered following compaction to near theoretical density, sub-stantially the balance of said mixture being said alloy-forming particles;
(d) compacting the powder mixture into an article of the desired configuration having a green density ranging from about 70 to 90 percent of theoretical density sufficient to render the so-formed article capable of being sintered to near theoretical density; and (e) sintering the article at an elevated temperature below that at which any liquid phase is formed in said article to produce a sintered, powdered metal alloy article having a density approaching theoretical.
12. The article of claim 11, wherein said alloy-forming particles are pre-alloyed particles.
13. The article of claim 12, wherein said pre-alloyed particles are an alloy of iron and silicon.
14. The article of claim 12, wherein said pre-alloyed particles are an alloy of vanadium and aluminum.
15. The article of claim 11, wherein said alloy-forming metal particles are composed of a metal selected from the group consisting of silicon, molybdenum, tungsten, chromium, nickel, vanadium and mixtures thereof.
16. The article of claim 11 wherein said base-metal particles are composed of a metal selected from the group consisting of titanium, iron, zirconium, nickel and alloys of such metals.
17. The sintered article of claim 11, wherein the alloy-forming particles are provided with said average particle size of about 0.5 to 20 microns by milling a charge of said alloy-forming particles.
18. The sintered article of claim 17, wherein said milling is done with a liquid and said liquid is a fluorocarbon.
19. The sintered article of claim 18, wherein said fluorocarbon is trichlorotrifluoroethane.
20. The sintered article of claim 17, wherein said milling is done with a liquid and said liquid is Freon.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US9750979A | 1979-11-26 | 1979-11-26 | |
| US06/097,509 | 1979-11-26 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1177287A true CA1177287A (en) | 1984-11-06 |
Family
ID=22263732
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000365197A Expired CA1177287A (en) | 1979-11-26 | 1980-11-21 | High density sintered powdered metal alloy and method of producing same |
Country Status (8)
| Country | Link |
|---|---|
| JP (1) | JPS56123301A (en) |
| AU (1) | AU539115B2 (en) |
| BR (1) | BR8007687A (en) |
| CA (1) | CA1177287A (en) |
| DE (1) | DE3043321A1 (en) |
| FR (1) | FR2469970A1 (en) |
| GB (1) | GB2065710B (en) |
| MX (1) | MX154581A (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61246333A (en) * | 1985-04-23 | 1986-11-01 | Honda Motor Co Ltd | Manufacture of high density ti sintered alloy |
| DE3530741C1 (en) * | 1985-08-28 | 1993-01-14 | Avesta Nyby Powder AB, Torshälla | Process for the manufacture of powder metallurgical objects |
| JPH02166201A (en) * | 1988-12-19 | 1990-06-26 | Kobe Steel Ltd | Manufacture of high density sintered body |
| US5167885A (en) * | 1992-01-07 | 1992-12-01 | W. R. Grace & Co.-Conn. | Method for making sintered bodies |
| US5898009A (en) * | 1996-03-19 | 1999-04-27 | Advanced Ceramics Corporation | High density agglomerated boron nitride particles |
| DE69807040T2 (en) * | 1998-02-16 | 2003-05-08 | Advanced Ceramics Corp | Process for forming high density boron nitride and agglomerated high density boron nitride particles |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2805624A (en) * | 1952-03-11 | 1957-09-10 | Olin Mathieson | Metallurgical process |
| US3744993A (en) * | 1970-11-30 | 1973-07-10 | Aerojet General Co | Powder metallurgy process |
| DE2333614A1 (en) * | 1973-07-02 | 1975-02-20 | Olin Corp | Powder metallurgy composite anode matrixes - as multi phase strip from coarse and fine materials |
| SE378260B (en) * | 1973-11-29 | 1975-08-25 | Hoeganaes Ab | |
| SE397780B (en) * | 1976-06-24 | 1977-11-21 | Hoeganaes Ab | KIT FOR PRODUCTION OF SINTER STEEL WITH HIGH STRENGTH AND GOOD DUCTIVITY |
| US4177069A (en) * | 1977-04-09 | 1979-12-04 | Showa Denko K.K. | Process for manufacturing sintered compacts of aluminum-base alloys |
| DE2819091C2 (en) * | 1978-04-29 | 1979-11-15 | Messer Griesheim Gmbh, 6000 Frankfurt | Use of a metal powder mixture |
-
1980
- 1980-11-17 DE DE19803043321 patent/DE3043321A1/en active Granted
- 1980-11-17 AU AU64445/80A patent/AU539115B2/en not_active Ceased
- 1980-11-21 CA CA000365197A patent/CA1177287A/en not_active Expired
- 1980-11-24 FR FR8024864A patent/FR2469970A1/en active Granted
- 1980-11-25 BR BR8007687A patent/BR8007687A/en unknown
- 1980-11-25 GB GB8037759A patent/GB2065710B/en not_active Expired
- 1980-11-26 JP JP16545280A patent/JPS56123301A/en active Granted
- 1980-11-26 MX MX184907A patent/MX154581A/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| FR2469970B1 (en) | 1985-01-18 |
| AU6444580A (en) | 1981-06-04 |
| JPS56123301A (en) | 1981-09-28 |
| DE3043321C2 (en) | 1990-10-31 |
| AU539115B2 (en) | 1984-09-13 |
| BR8007687A (en) | 1981-06-09 |
| JPH0250172B2 (en) | 1990-11-01 |
| FR2469970A1 (en) | 1981-05-29 |
| GB2065710B (en) | 1984-07-11 |
| DE3043321A1 (en) | 1981-05-27 |
| MX154581A (en) | 1987-10-07 |
| GB2065710A (en) | 1981-07-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5108493A (en) | Steel powder admixture having distinct prealloyed powder of iron alloys | |
| EP0374358B1 (en) | High strength nitrogen-containing cermet and process for preparation thereof | |
| EP0534191B1 (en) | Cermets and their production and use | |
| EP1054071B1 (en) | Method of manfacturing an improved fine-grained WC-Co cemented carbide | |
| US4379719A (en) | Aluminum powder alloy product for high temperature application | |
| US5482670A (en) | Cemented carbide | |
| US4464199A (en) | Aluminum powder alloy product for high temperature application | |
| CA2811754C (en) | Aluminum powder metal alloying method | |
| US6365095B1 (en) | Warm compaction of steel powders | |
| CN110102752A (en) | A kind of cermet solid solution alloy powder and preparation method | |
| US5993507A (en) | Composition and process for metal injection molding | |
| EP0417333B1 (en) | Cermet and process of producing the same | |
| US4432795A (en) | Sintered powdered titanium alloy and method of producing same | |
| EP0477685A2 (en) | Cermets and their production and use | |
| JP2919073B2 (en) | Stamping method as sintered | |
| CA1177287A (en) | High density sintered powdered metal alloy and method of producing same | |
| US5217683A (en) | Steel powder composition | |
| US4343650A (en) | Metal binder in compaction of metal powders | |
| US6312497B1 (en) | Pre-alloyed, copper containing powder, and its use in the manufacture of diamond tools | |
| EP0366134B1 (en) | Aluminum alloy useful in powder metallurgy process | |
| US4702772A (en) | Sintered alloy | |
| EP0323628B1 (en) | Fine grain tungsten heavy alloys containing additives | |
| US4015947A (en) | Production of sintered aluminum alloy articles from particulate premixes | |
| CA1049296A (en) | Powder-metallurgy of cobalt containing brass alloys | |
| US4986961A (en) | Fine grain tungsten heavy alloys containing additives |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |