CA2130746A1 - Metal matrix alloys - Google Patents
Metal matrix alloysInfo
- Publication number
- CA2130746A1 CA2130746A1 CA002130746A CA2130746A CA2130746A1 CA 2130746 A1 CA2130746 A1 CA 2130746A1 CA 002130746 A CA002130746 A CA 002130746A CA 2130746 A CA2130746 A CA 2130746A CA 2130746 A1 CA2130746 A1 CA 2130746A1
- Authority
- CA
- Canada
- Prior art keywords
- titanium
- reaction mixture
- boron
- reaction
- particles
- 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.)
- Abandoned
Links
Classifications
-
- 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)
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C29/00—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides
- C22C29/14—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides based on borides
Abstract
The invention provides a method of making a titanium boride metal matrix alloy, by firing a particulate reaction mixture comprising titanium, matrix material and a source of boron (e.g. boron carbide), under conditions such that the titanium and boron react exothermically to form a dispersion of fine particles (preferably greater than 1 micron and less than 10 microns in size) comprising titanium boride (plus titanium carbide where the source of boron is boron carbide) in a predominantly metal matrix. The titanium and matrix are preferably added as a titanium alloy such as ferrotitanium (e.g. eutectic ferrotitanium) or titanium-aluminium. The reaction conditions are preferably selected so that during the reaction a molten zone moves through the body of the reaction mixture, and the average size of the resulting hard particles is uniform throughout the resulting dispersion.
Description
Metal Ma1:rix Alloys ~ ~. 3 0 7 4 ~
This invention relates to a method of making an alloy compnsing hard particles compnsing titanium boride dispersed in a predominantly metal matrix, and to the resulting alloy itself. Alloys of the aforementioned kind are hereinafter referred to as titanium boride metal matrLlc alloys.
Our U. K. patent application no. 9116174.5, which was filed on 26th July 1991, and which was published on 27th January 1993 as GB 2257985 A, describes and claims a me~od of ma~ing an alloy comprising hard par~cles comprising ~tanium carbide dispersed in a predominantly metal matri~c, the method comprising firing a par~culate reaction mixture comprising ca~bon, titanium and matri~c mate~ial, under conditions such that the titanium and carbon react exothermically to form a dispersion of fine particles comprising titanium caioide in a predominantly metal matrix.
According to the present invention, there is provided a method of making an alloy comp~ising hard particles comprising titanium boride dispersed in a predominantly metal ~-ma~, the method comprising finng a particulatc reac~on mi~cture comprising titanium, matrLl~ material and a source of boron, under conditions such that the titanium and boron react e~cothermically to form a dispersion of fine particles comprising titanium boride in a predominantly metal mat~Llc.
It is surprising that the e~cothermic reaction of the method of the invention is capable of producing a dispersion of fine, hard partides in the mat~i~. Howcver, we have found that it is possible, using simple trial and e~ e~periments, to find suitable conditions to achiwe that end, when the following principles are borne in mind:
(i) It is highly desirable to adjust the reaction conditions such that ~e e~cothennic reaction is carried out under conditions such that during the reaction a molten ~one moves through the body of the reaction mi~ctL~re, so that at a given point during reaction the reaction mi~ture ahead of the reaction zone is solid, and so is ~atbehind the Ieaction zone.
(ii) The hard particles may be of gener~lly globular shape. That would indicate that the reaction zone had reached a sufficiently high temperature to allow precipitation of ~e hard par~cles. However, in many preferred embodiments of theinvention, at least some of the hard par~cles may be of angular shape, and indeed in many cases they are all thus shaped.
WO 94117219 ~ PCTtGB94/00109 (iii) ln order to promote uniformity of reaction conditions, and thus also uniformity of the physical properties of the product, the buLk of the reaction mixture should not be too small (unlikely to occur in prac~ce) or too large. Success in this regard can readily be assessed by observing the uniformity of the particle size of the hardparticles formed throughout the reac~on mixture. Preferably, the average par~clesize of the hard particles is substantially unifonn throughout the resulting dispersion.
.
(iv) The longer the hard particles are present in a melt before solidification, the larger ~;
their final size will be. If the hard par~cles are found to be undesirably largethrough being present in a melt for too long a time, the proeess conditions can be adjusted so that the temperature reached in ~e reaction is decreased and/or the cooling rate is increased.
(v) The temperature reached in the e~othennic reaction can be decreased by one or more of the following measures:
(a) dec;G~ng the concentration of thc reac~nts, e.g. by increasing the -~
concentration of matrLlc material;
(b) increasing the particle size of the reactants; and (c) decreasing the wdght of the reaction mi~ture.
(d) replacing a part of the titanium reactant by an additional calbide-forming rea~tant which reacls with the carbon less e~othermically than does the titanium reactant.
The t~mperature can, of course, be increased by reversing one or more of (a), (b), (c) and (d). -~
Generally, the titanium boride present in the product of the method of the invention ~ -will be in the form of titanium diboride. -It will be appreciated ~at in the method of the invention, the particulate reaction ~ ture which is fired may include reactable materials in addition to the source of boron and the titanium, which additional reactable materials may be present in the matri~ material or othen~vise; for e~ample chromium, tungsten, vanadium, niobium, carbon and/or nitrogen. The resulting fine particles comprising titanium boride will therefore not necessarily consist of titanium boride as such.
Desirably, the available titanium content of the reaction mi~cture is equal to at least 30% by weigh~, and preferably greater than 50% and less than 70% by weight, of the total WO 94117219 ~ ~ ~ U ~ 4 ~ PCTIGB94100109 weight of the reaction mixture (the term "reaction mixture" as used herein means the total ~-of all the materials present in the reaction body, including any which do not undergo any -;
chemical reaction in the method of the invention and which may in effect be a diluent) This will generally enable sufficient heat to be generated in the exothermic reaction, and a useful concentration of hard particles to be formed in the product.
The source of boron ip the reaction mixture may be boron itself, in ~e form of boron powder, for example. However, we prefer that the source of boron should comprise a suitable compound of boron, preferably boron car'oide, B4C.
The matrix metal may be based on iron or aluminium, for example. It may be possible for the matrix metal to be based on other metals such as nickel, cobalt or copper, for example. We prefer that substantially all of the titanium should be present in the reaction mixture as an alloy of matrix metal and titanium. However, some or, in less preferred embodimen~s all, of the matrLlc metal may be present in the reaction mixture unalloyed with titanium. Where the product alloy is to be iron-based, we prefer that the -titanium should be present in the reaction mL~cture as ferrotitanium, and most preferably as eutectic ferrotitanium, which contains about 70% by weight titanium. In the latter ca~e, we have found that a suitable particle size ~or the eutectic ferrotitanium is generally in the range 0.5 mm down to 3.0 mm down.
Where the product alloy is to be aluminium-based, we prefer that the titanium should be present in the reaction n~ixture as titanium-alun~inium, wherein the dtznium content is preferably about 60% by weight, and the particle size is preferably about 300 mlcrons down.
In some instances, for example where the concentration of titanium in the reaction mixtur~ is particularly low, the reaction mi~ture may need to be pre-heated in order to get it to fire and react without further heat input. However, we prefer that the temperature of the body of the reaction mixture should be at less than 600C, and preferably at less than 500C, immediately prior to firing.
We most prefer that the temperature of the body of the particulate reaction mi~cture is substantially at ambient temperature (i.e. at no more than 100C) immediately prior to firing. Where a particular reaction mi~cture will not fire at ambient tempe~ature, it may be modified, using the principles described above, so that it can be fired at ambient temperature and react without requiring fur~er heat input.
W~ 94tl7219 ~ ~ ~ V 7 '~ 4 PCT/GB94/00109 ~ ~
Preferably the particulate reachon mixture which is fired is a loose mixture (i.e. a mixture which, although it may have been packed, has not been compressed to such an extent as to cause it to become fully cohesive, as occurs in briquetting). We have found that briquetting of the reaction mixture very much reduces its ability to be fired so as to produce a self-sustaining reaction. For the sarne reason, the reaction mixture, if packed at all, is preferably not compressed sufficiently to produce any substantial degree of cohesion.
The firing of the particulate reaction mixture in the method according to the invention may be performed in any suitable manner. For example, an ignitable fi ing -material (e.g. titanium particles) may be positioned at the surface of the particulate reaction mixture and sufficient heat applied to the ignitable material to cause ignition. Altematively, the particulate reaction mixture may be fired by heating in such a way that an outer skin of the par~culate reaction mixture is heated to a high temperature, sufficient to initiate the exothemlic reaction, the body of the particulate reaction mixture having undergone relatively little heating at that stage; this can be achieved by, for example, heating the particulate reaction mixture in a heat-inducing (e.g. clay graphite or silicon ca~oide ) cnucible, in a coreless induction furnace.
For most end uses of the product, we prefer that the amount of the source of boron in the reaction mLlcture should be substantially the stoichiometric amount required to react with all of the available titanium in the reaction n~ixture. In par~cular, in the preferred embodiment where the source of boron is boron carbide, we prefer that the amount of B4C
is such that the total amount of boron and carbon in it is stoichiometrically equivalent to the available titanium.
We have found that by practising the invention talcing into account the points ,discussed above, it is easily possible to arrange that the average particle size of the hard particles in the product is less than 25 microns, and an average particle size of less than 10 microns can be achieved without difficulty; generally the average particle size will be greater than 1 micron.
In accordance with a preferred embodiment, the method of the invention comprisesfiring a reaction mLxtuFe comprising boron carbide and crushed eutectic ferrotitanium under conditions such that a molten zone moves through the body of the reaction n~i~ture, to form a dispersion of a mixture of titanium diboride particles and titanium carbide particles of .
average particle size 8reater than 1 micron and less than 10 microns in a ferrous metal matrix.
~ 1 ~ a 7 1 ~J :
WO 94117219 PCl'IGB~4/00109 For many end uses it is desirable to reduce the dispersion produced by the method of the invention to a powder; one having an average particle size of less than 250 microns is preferred.
In order that the invention may be more fully understood, some preferred embodiments in accordance therewith will now be described in the following Examples, with reference to the a~companying drawings wherein:
Fig. 1 shows a scann~ng electron micrograph, at a magnification of 1000, of the alloy produced in Esample 1.
Fig. 2 shows a photomicrograph, at a magnification of 1000, of the alloy produced in E~ample 2.
Exam~le 1.
1 kg of eutectic ferrotitanium (70 % titanium, by weight) produced by London &
Scandinavian Metallurgical Co Limited were crushed to less than 2 mm. This was then mi~ted with 267 g of bor~n carbide (B4C) ground to less than 500 microns. The mi~cture was loosely packed into a refractory lined vessel. The mi~cture was ignited by forn~ing a depression in its top surface, which was filled with titanium sponge powder, to which a flame was applied.
Once ignited, an e~co~ens~ic reaction propagated throughout the whole of the powder bed, such that, at a given point during the reaction the reaction mi~ture ahead of the ,reaction zone was solid, the reactiol}zone itself was liquid and the reacted mat~ial behind the reaction zone was solid.
After cooling, the product wæ crushed to a 2 mm down powder. Pigure 1 is a scanning electron micrograph of the product, and shows that it consists of a uniform dispersion of a larger proportion of TiB2 particles (about 53 9ti by weigh~ of the product, as those shown at 1) and a lesser number of TiC particles (about 23% by weight of the product, as those which can be seen relatively raised at 2) in an iron matrix (about 24% by weight of the product, as can be seen at 3). This pr~portion is consistent with the stoichiometry of the B4C and PeTi reactants. The mounting resin can be seen at 4.
WO 94117219 i 7 ~ ~; PCT/GB94/OOlog Examplç_2 1 kg of titanium-aluminium powder (60% ~itanium by weight) produced by London & Scandinavian Metallurgical Co Limited having a particle size less than 300 microns were mixed with 229 g of boron carbide of less than 500 microns particle size The mixture was loosely packed into a refractory lined vessel and fired as in Exarnple 1.
Once ignited an e~othennic reaction propagated throughout the whole of the powder bed, such that, at a given point during the reaction, the reaction mixture ahead of the -~
reaction ~one was solid, the reaction zone itself was liquid and the reacted material behind the reaction zone was solid.
After cooling, the product was comminuted. Pigure 2 is a photomicrograph of the -~
product, and shows that it consists of a uniform dispersion of TiB2 particles (as those shown at 21) and TiC particles (as those shown at 22) in an aluminium matrix (as shown at -~
23).
Example ~ ~
.:' 300 g of crushed eutec~ic ferrotita~ium as used in EJ~ample 1 weré mixed with 94.5 g of fine boron powder ha~ing a particle size of 45 microns down. The mixture was loosely packed into a refractory lined vessel and fired as in Example 1.
Once ignited, a very vigorous exothermic reaction propagated throughout the whole of the powder bed, such that, at a given point during the reaction the reaction n~i~ture ahead ~ -, of the reaction zone was solid, the reaction zone itself was liquid and the reacted material behind the reaction zone wæ solid.
After cooling, the product was comminuted. It consisted of a uniform dispersion of TiB2 palticles in an iron matrix.
This invention relates to a method of making an alloy compnsing hard particles compnsing titanium boride dispersed in a predominantly metal matrix, and to the resulting alloy itself. Alloys of the aforementioned kind are hereinafter referred to as titanium boride metal matrLlc alloys.
Our U. K. patent application no. 9116174.5, which was filed on 26th July 1991, and which was published on 27th January 1993 as GB 2257985 A, describes and claims a me~od of ma~ing an alloy comprising hard par~cles comprising ~tanium carbide dispersed in a predominantly metal matri~c, the method comprising firing a par~culate reaction mixture comprising ca~bon, titanium and matri~c mate~ial, under conditions such that the titanium and carbon react exothermically to form a dispersion of fine particles comprising titanium caioide in a predominantly metal matrix.
According to the present invention, there is provided a method of making an alloy comp~ising hard particles comprising titanium boride dispersed in a predominantly metal ~-ma~, the method comprising finng a particulatc reac~on mi~cture comprising titanium, matrLl~ material and a source of boron, under conditions such that the titanium and boron react e~cothermically to form a dispersion of fine particles comprising titanium boride in a predominantly metal mat~Llc.
It is surprising that the e~cothermic reaction of the method of the invention is capable of producing a dispersion of fine, hard partides in the mat~i~. Howcver, we have found that it is possible, using simple trial and e~ e~periments, to find suitable conditions to achiwe that end, when the following principles are borne in mind:
(i) It is highly desirable to adjust the reaction conditions such that ~e e~cothennic reaction is carried out under conditions such that during the reaction a molten ~one moves through the body of the reaction mi~ctL~re, so that at a given point during reaction the reaction mi~ture ahead of the reaction zone is solid, and so is ~atbehind the Ieaction zone.
(ii) The hard particles may be of gener~lly globular shape. That would indicate that the reaction zone had reached a sufficiently high temperature to allow precipitation of ~e hard par~cles. However, in many preferred embodiments of theinvention, at least some of the hard par~cles may be of angular shape, and indeed in many cases they are all thus shaped.
WO 94117219 ~ PCTtGB94/00109 (iii) ln order to promote uniformity of reaction conditions, and thus also uniformity of the physical properties of the product, the buLk of the reaction mixture should not be too small (unlikely to occur in prac~ce) or too large. Success in this regard can readily be assessed by observing the uniformity of the particle size of the hardparticles formed throughout the reac~on mixture. Preferably, the average par~clesize of the hard particles is substantially unifonn throughout the resulting dispersion.
.
(iv) The longer the hard particles are present in a melt before solidification, the larger ~;
their final size will be. If the hard par~cles are found to be undesirably largethrough being present in a melt for too long a time, the proeess conditions can be adjusted so that the temperature reached in ~e reaction is decreased and/or the cooling rate is increased.
(v) The temperature reached in the e~othennic reaction can be decreased by one or more of the following measures:
(a) dec;G~ng the concentration of thc reac~nts, e.g. by increasing the -~
concentration of matrLlc material;
(b) increasing the particle size of the reactants; and (c) decreasing the wdght of the reaction mi~ture.
(d) replacing a part of the titanium reactant by an additional calbide-forming rea~tant which reacls with the carbon less e~othermically than does the titanium reactant.
The t~mperature can, of course, be increased by reversing one or more of (a), (b), (c) and (d). -~
Generally, the titanium boride present in the product of the method of the invention ~ -will be in the form of titanium diboride. -It will be appreciated ~at in the method of the invention, the particulate reaction ~ ture which is fired may include reactable materials in addition to the source of boron and the titanium, which additional reactable materials may be present in the matri~ material or othen~vise; for e~ample chromium, tungsten, vanadium, niobium, carbon and/or nitrogen. The resulting fine particles comprising titanium boride will therefore not necessarily consist of titanium boride as such.
Desirably, the available titanium content of the reaction mi~cture is equal to at least 30% by weigh~, and preferably greater than 50% and less than 70% by weight, of the total WO 94117219 ~ ~ ~ U ~ 4 ~ PCTIGB94100109 weight of the reaction mixture (the term "reaction mixture" as used herein means the total ~-of all the materials present in the reaction body, including any which do not undergo any -;
chemical reaction in the method of the invention and which may in effect be a diluent) This will generally enable sufficient heat to be generated in the exothermic reaction, and a useful concentration of hard particles to be formed in the product.
The source of boron ip the reaction mixture may be boron itself, in ~e form of boron powder, for example. However, we prefer that the source of boron should comprise a suitable compound of boron, preferably boron car'oide, B4C.
The matrix metal may be based on iron or aluminium, for example. It may be possible for the matrix metal to be based on other metals such as nickel, cobalt or copper, for example. We prefer that substantially all of the titanium should be present in the reaction mixture as an alloy of matrix metal and titanium. However, some or, in less preferred embodimen~s all, of the matrLlc metal may be present in the reaction mixture unalloyed with titanium. Where the product alloy is to be iron-based, we prefer that the -titanium should be present in the reaction mL~cture as ferrotitanium, and most preferably as eutectic ferrotitanium, which contains about 70% by weight titanium. In the latter ca~e, we have found that a suitable particle size ~or the eutectic ferrotitanium is generally in the range 0.5 mm down to 3.0 mm down.
Where the product alloy is to be aluminium-based, we prefer that the titanium should be present in the reaction n~ixture as titanium-alun~inium, wherein the dtznium content is preferably about 60% by weight, and the particle size is preferably about 300 mlcrons down.
In some instances, for example where the concentration of titanium in the reaction mixtur~ is particularly low, the reaction mi~ture may need to be pre-heated in order to get it to fire and react without further heat input. However, we prefer that the temperature of the body of the reaction mixture should be at less than 600C, and preferably at less than 500C, immediately prior to firing.
We most prefer that the temperature of the body of the particulate reaction mi~cture is substantially at ambient temperature (i.e. at no more than 100C) immediately prior to firing. Where a particular reaction mi~cture will not fire at ambient tempe~ature, it may be modified, using the principles described above, so that it can be fired at ambient temperature and react without requiring fur~er heat input.
W~ 94tl7219 ~ ~ ~ V 7 '~ 4 PCT/GB94/00109 ~ ~
Preferably the particulate reachon mixture which is fired is a loose mixture (i.e. a mixture which, although it may have been packed, has not been compressed to such an extent as to cause it to become fully cohesive, as occurs in briquetting). We have found that briquetting of the reaction mixture very much reduces its ability to be fired so as to produce a self-sustaining reaction. For the sarne reason, the reaction mixture, if packed at all, is preferably not compressed sufficiently to produce any substantial degree of cohesion.
The firing of the particulate reaction mixture in the method according to the invention may be performed in any suitable manner. For example, an ignitable fi ing -material (e.g. titanium particles) may be positioned at the surface of the particulate reaction mixture and sufficient heat applied to the ignitable material to cause ignition. Altematively, the particulate reaction mixture may be fired by heating in such a way that an outer skin of the par~culate reaction mixture is heated to a high temperature, sufficient to initiate the exothemlic reaction, the body of the particulate reaction mixture having undergone relatively little heating at that stage; this can be achieved by, for example, heating the particulate reaction mixture in a heat-inducing (e.g. clay graphite or silicon ca~oide ) cnucible, in a coreless induction furnace.
For most end uses of the product, we prefer that the amount of the source of boron in the reaction mLlcture should be substantially the stoichiometric amount required to react with all of the available titanium in the reaction n~ixture. In par~cular, in the preferred embodiment where the source of boron is boron carbide, we prefer that the amount of B4C
is such that the total amount of boron and carbon in it is stoichiometrically equivalent to the available titanium.
We have found that by practising the invention talcing into account the points ,discussed above, it is easily possible to arrange that the average particle size of the hard particles in the product is less than 25 microns, and an average particle size of less than 10 microns can be achieved without difficulty; generally the average particle size will be greater than 1 micron.
In accordance with a preferred embodiment, the method of the invention comprisesfiring a reaction mLxtuFe comprising boron carbide and crushed eutectic ferrotitanium under conditions such that a molten zone moves through the body of the reaction n~i~ture, to form a dispersion of a mixture of titanium diboride particles and titanium carbide particles of .
average particle size 8reater than 1 micron and less than 10 microns in a ferrous metal matrix.
~ 1 ~ a 7 1 ~J :
WO 94117219 PCl'IGB~4/00109 For many end uses it is desirable to reduce the dispersion produced by the method of the invention to a powder; one having an average particle size of less than 250 microns is preferred.
In order that the invention may be more fully understood, some preferred embodiments in accordance therewith will now be described in the following Examples, with reference to the a~companying drawings wherein:
Fig. 1 shows a scann~ng electron micrograph, at a magnification of 1000, of the alloy produced in Esample 1.
Fig. 2 shows a photomicrograph, at a magnification of 1000, of the alloy produced in E~ample 2.
Exam~le 1.
1 kg of eutectic ferrotitanium (70 % titanium, by weight) produced by London &
Scandinavian Metallurgical Co Limited were crushed to less than 2 mm. This was then mi~ted with 267 g of bor~n carbide (B4C) ground to less than 500 microns. The mi~cture was loosely packed into a refractory lined vessel. The mi~cture was ignited by forn~ing a depression in its top surface, which was filled with titanium sponge powder, to which a flame was applied.
Once ignited, an e~co~ens~ic reaction propagated throughout the whole of the powder bed, such that, at a given point during the reaction the reaction mi~ture ahead of the ,reaction zone was solid, the reactiol}zone itself was liquid and the reacted mat~ial behind the reaction zone was solid.
After cooling, the product wæ crushed to a 2 mm down powder. Pigure 1 is a scanning electron micrograph of the product, and shows that it consists of a uniform dispersion of a larger proportion of TiB2 particles (about 53 9ti by weigh~ of the product, as those shown at 1) and a lesser number of TiC particles (about 23% by weight of the product, as those which can be seen relatively raised at 2) in an iron matrix (about 24% by weight of the product, as can be seen at 3). This pr~portion is consistent with the stoichiometry of the B4C and PeTi reactants. The mounting resin can be seen at 4.
WO 94117219 i 7 ~ ~; PCT/GB94/OOlog Examplç_2 1 kg of titanium-aluminium powder (60% ~itanium by weight) produced by London & Scandinavian Metallurgical Co Limited having a particle size less than 300 microns were mixed with 229 g of boron carbide of less than 500 microns particle size The mixture was loosely packed into a refractory lined vessel and fired as in Exarnple 1.
Once ignited an e~othennic reaction propagated throughout the whole of the powder bed, such that, at a given point during the reaction, the reaction mixture ahead of the -~
reaction ~one was solid, the reaction zone itself was liquid and the reacted material behind the reaction zone was solid.
After cooling, the product was comminuted. Pigure 2 is a photomicrograph of the -~
product, and shows that it consists of a uniform dispersion of TiB2 particles (as those shown at 21) and TiC particles (as those shown at 22) in an aluminium matrix (as shown at -~
23).
Example ~ ~
.:' 300 g of crushed eutec~ic ferrotita~ium as used in EJ~ample 1 weré mixed with 94.5 g of fine boron powder ha~ing a particle size of 45 microns down. The mixture was loosely packed into a refractory lined vessel and fired as in Example 1.
Once ignited, a very vigorous exothermic reaction propagated throughout the whole of the powder bed, such that, at a given point during the reaction the reaction n~i~ture ahead ~ -, of the reaction zone was solid, the reaction zone itself was liquid and the reacted material behind the reaction zone wæ solid.
After cooling, the product was comminuted. It consisted of a uniform dispersion of TiB2 palticles in an iron matrix.
Claims (22)
1. A method of making an alloy comprising hard particles comprising titanium boride dispersed in a predominantly metal matrix, the method comprising firing a particulate reaction mixture comprising titanium, matrix material and a source of boron, under conditions such that the titanium and boron react exothermically to form a dispersion of fine particles comprising titanium boride in a predominantly metal matrix.
2. A method according to claim 1, wherein the exothermic reaction is carried out under conditions such that during the reaction a molten zone moves through the body of the reaction mixture.
3. A method according to claim 1 or claim 2, wherein the average particle size of the particles comprising titanium boride is substantially uniform throughout the resulting dispersion.
4. A method according to any one of claims 1 to 3, wherein the available titanium content of the reaction mixture is equal to at least 30% by weight, and preferably greater than 50%
and less than 70% by weight, of the total weight of the reaction mixture.
and less than 70% by weight, of the total weight of the reaction mixture.
5. A method according to any one of claims 1 to 4, wherein the source of boron in the reaction mixture comprises a compound of boron.
6. A method according to any one of claims 1 to 5, wherein the source of boron in the reaction mixture comprises boron carbide.
7. A method according to any one of claims 1 to 6, wherein titanium is present in the reaction mixture as an alloy of matrix metal and titanium.
8. A method according to claim 7, wherein titanium is present in the reaction mixture as ferrotitanium.
9. A method according to claim 8, wherein titanium is present in the reaction mixture as eutectic ferrotitanium.
10. A method according to claim 9, wherein the particle size of the eutectic ferrotitanium is in the range 0.5 mm down to 3.0 mm down.
11. A method according to claim 7, wherein titanium is present in the reaction mixture as an alloy comprising aluminium and titanium.
12. A method according to claim 11, wherein the alloy comprising aluminium and titanium comprises about 70% by weight of titanium.
13. A method according to any one of claims 1 to 12, wherein the body of the particulate reaction mixture is at less than 600°C, and preferably at less than 500°C, immediately prior to firing.
14. A method according to claim 13, wherein the body of the particulate reaction mixture is substantially at ambient temperature immediately prior to firing.
15. A method according to any one of claims 1 to 14, wherein the particulate reaction mixture which is fired is a loose mixture.
16. A method according to any one of claims 1 to 15, wherein the average particle size of the particles comprising titanium boride is less than 25 microns.
17. A method according to claim 16, wherein the average particle size of the particles comprising titanium boride is greater than 1 micron and less than 10 microns.
18. A method according to claim 1, comprising firing a reaction mixture comprising boron carbide and crushed eutectic ferrotitanium under conditions such that a molten zone moves through the body of the reaction mixture, to form a dispersion of a mixture of titanium diboride particles and titanium carbide particles of average particle size greater than 1 micron and less than 10 microns in a ferrous metal matrix.
19. A method according to any one of claims 1 to 18, wherein the dispersion is reduced to a powder.
20. A method according to claim 19, wherein the dispersion is reduced to a powder of average particle size less than 250 microns.
21. A method according to claim 1, substantially as described in any one of the foregoing Examples 1 to 3.
22. A dispersion of fine particles comprising titanium boride in a predominantly metal matrix, whenever produced by a method in accordance with any one of claims 1 to 21.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9301458A GB2274467A (en) | 1993-01-26 | 1993-01-26 | Metal matrix alloys |
| GB9301458.7 | 1993-01-26 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2130746A1 true CA2130746A1 (en) | 1994-08-04 |
Family
ID=10729305
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002130746A Abandoned CA2130746A1 (en) | 1993-01-26 | 1994-01-20 | Metal matrix alloys |
Country Status (7)
| Country | Link |
|---|---|
| US (1) | US6099664A (en) |
| EP (1) | EP0632845A1 (en) |
| JP (1) | JPH07505680A (en) |
| CA (1) | CA2130746A1 (en) |
| GB (1) | GB2274467A (en) |
| WO (1) | WO1994017219A1 (en) |
| ZA (1) | ZA94279B (en) |
Families Citing this family (29)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5708956A (en) * | 1995-10-02 | 1998-01-13 | The Dow Chemical Company | Single step synthesis and densification of ceramic-ceramic and ceramic-metal composite materials |
| DE19601234A1 (en) | 1996-01-15 | 1997-07-17 | Widia Gmbh | Composite body and process for its manufacture |
| US6193928B1 (en) | 1997-02-20 | 2001-02-27 | Daimlerchrysler Ag | Process for manufacturing ceramic metal composite bodies, the ceramic metal composite bodies and their use |
| US7416697B2 (en) | 2002-06-14 | 2008-08-26 | General Electric Company | Method for preparing a metallic article having an other additive constituent, without any melting |
| US7531021B2 (en) * | 2004-11-12 | 2009-05-12 | General Electric Company | Article having a dispersion of ultrafine titanium boride particles in a titanium-base matrix |
| US20070017319A1 (en) | 2005-07-21 | 2007-01-25 | International Titanium Powder, Llc. | Titanium alloy |
| US7776256B2 (en) | 2005-11-10 | 2010-08-17 | Baker Huges Incorporated | Earth-boring rotary drill bits and methods of manufacturing earth-boring rotary drill bits having particle-matrix composite bit bodies |
| US8002052B2 (en) * | 2005-09-09 | 2011-08-23 | Baker Hughes Incorporated | Particle-matrix composite drill bits with hardfacing |
| US7997359B2 (en) | 2005-09-09 | 2011-08-16 | Baker Hughes Incorporated | Abrasive wear-resistant hardfacing materials, drill bits and drilling tools including abrasive wear-resistant hardfacing materials |
| US7597159B2 (en) | 2005-09-09 | 2009-10-06 | Baker Hughes Incorporated | Drill bits and drilling tools including abrasive wear-resistant materials |
| US7703555B2 (en) | 2005-09-09 | 2010-04-27 | Baker Hughes Incorporated | Drilling tools having hardfacing with nickel-based matrix materials and hard particles |
| US20070079908A1 (en) * | 2005-10-06 | 2007-04-12 | International Titanium Powder, Llc | Titanium boride |
| CN1317407C (en) * | 2005-11-07 | 2007-05-23 | 北京科技大学 | Method for producing steel bonded carbide |
| CN1317408C (en) * | 2005-11-08 | 2007-05-23 | 北京科技大学 | Process for preparing metal-ceramic gradient material |
| US7784567B2 (en) | 2005-11-10 | 2010-08-31 | Baker Hughes Incorporated | Earth-boring rotary drill bits including bit bodies comprising reinforced titanium or titanium-based alloy matrix materials, and methods for forming such bits |
| US8770324B2 (en) * | 2008-06-10 | 2014-07-08 | Baker Hughes Incorporated | Earth-boring tools including sinterbonded components and partially formed tools configured to be sinterbonded |
| US7802495B2 (en) | 2005-11-10 | 2010-09-28 | Baker Hughes Incorporated | Methods of forming earth-boring rotary drill bits |
| US7807099B2 (en) | 2005-11-10 | 2010-10-05 | Baker Hughes Incorporated | Method for forming earth-boring tools comprising silicon carbide composite materials |
| US7913779B2 (en) * | 2005-11-10 | 2011-03-29 | Baker Hughes Incorporated | Earth-boring rotary drill bits including bit bodies having boron carbide particles in aluminum or aluminum-based alloy matrix materials, and methods for forming such bits |
| US7731776B2 (en) * | 2005-12-02 | 2010-06-08 | Exxonmobil Research And Engineering Company | Bimodal and multimodal dense boride cermets with superior erosion performance |
| EP2066864A1 (en) | 2006-08-30 | 2009-06-10 | Baker Hughes Incorporated | Methods for applying wear-resistant material to exterior surfaces of earth-boring tools and resulting structures |
| US8272295B2 (en) * | 2006-12-07 | 2012-09-25 | Baker Hughes Incorporated | Displacement members and intermediate structures for use in forming at least a portion of bit bodies of earth-boring rotary drill bits |
| US7775287B2 (en) | 2006-12-12 | 2010-08-17 | Baker Hughes Incorporated | Methods of attaching a shank to a body of an earth-boring drilling tool, and tools formed by such methods |
| US7753989B2 (en) | 2006-12-22 | 2010-07-13 | Cristal Us, Inc. | Direct passivation of metal powder |
| US7841259B2 (en) | 2006-12-27 | 2010-11-30 | Baker Hughes Incorporated | Methods of forming bit bodies |
| US9127333B2 (en) | 2007-04-25 | 2015-09-08 | Lance Jacobsen | Liquid injection of VCL4 into superheated TiCL4 for the production of Ti-V alloy powder |
| US8261632B2 (en) * | 2008-07-09 | 2012-09-11 | Baker Hughes Incorporated | Methods of forming earth-boring drill bits |
| BE1018130A3 (en) * | 2008-09-19 | 2010-05-04 | Magotteaux Int | HIERARCHICAL COMPOSITE MATERIAL. |
| BE1018129A3 (en) * | 2008-09-19 | 2010-05-04 | Magotteaux Int | COMPOSITE IMPACTOR FOR PERCUSSION CRUSHERS. |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB808270A (en) * | 1956-09-05 | 1959-01-28 | Union Carbide Corp | Improvements in and relating to titanium-base alloys |
| US3726643A (en) * | 1970-04-09 | 1973-04-10 | I Khim Fiz Akademii Nauk | Method of producing refractory carbides,borides,silicides,sulfides,and nitrides of metals of groups iv,v,and vi of the periodic system |
| BE794959A (en) * | 1972-02-04 | 1975-04-14 | ||
| LU67355A1 (en) * | 1973-04-04 | 1974-11-21 | ||
| GB1431145A (en) * | 1974-05-13 | 1976-04-07 | Inst Litya Akademii Nauk Uk Ss | Inoculants for iron-based an nickel-based alloys |
| AT377784B (en) * | 1980-02-20 | 1985-04-25 | Inst Khim Fiz An Sssr | TUNGSTEN-FREE HARD ALLOY AND METHOD FOR THEIR PRODUCTION |
| US4836982A (en) * | 1984-10-19 | 1989-06-06 | Martin Marietta Corporation | Rapid solidification of metal-second phase composites |
| US5015534A (en) * | 1984-10-19 | 1991-05-14 | Martin Marietta Corporation | Rapidly solidified intermetallic-second phase composites |
| US4915908A (en) * | 1984-10-19 | 1990-04-10 | Martin Marietta Corporation | Metal-second phase composites by direct addition |
| US4673550A (en) * | 1984-10-23 | 1987-06-16 | Serge Dallaire | TiB2 -based materials and process of producing the same |
| US4777014A (en) * | 1986-03-07 | 1988-10-11 | Lanxide Technology Company, Lp | Process for preparing self-supporting bodies and products made thereby |
| US4772452A (en) * | 1986-12-19 | 1988-09-20 | Martin Marietta Corporation | Process for forming metal-second phase composites utilizing compound starting materials |
| US4999050A (en) * | 1988-08-30 | 1991-03-12 | Sutek Corporation | Dispersion strengthened materials |
| GB2257985A (en) * | 1991-07-26 | 1993-01-27 | London Scandinavian Metall | Metal matrix alloys. |
| GB2259309A (en) * | 1991-09-09 | 1993-03-10 | London Scandinavian Metall | Ceramic particles |
| US5301739A (en) * | 1992-06-30 | 1994-04-12 | Cook Arnold J | Method for casting and densification |
| US5708956A (en) * | 1995-10-02 | 1998-01-13 | The Dow Chemical Company | Single step synthesis and densification of ceramic-ceramic and ceramic-metal composite materials |
-
1993
- 1993-01-26 GB GB9301458A patent/GB2274467A/en not_active Withdrawn
-
1994
- 1994-01-14 ZA ZA94279A patent/ZA94279B/en unknown
- 1994-01-20 WO PCT/GB1994/000109 patent/WO1994017219A1/en not_active Application Discontinuation
- 1994-01-20 EP EP94904292A patent/EP0632845A1/en not_active Withdrawn
- 1994-01-20 CA CA002130746A patent/CA2130746A1/en not_active Abandoned
- 1994-01-20 JP JP6516797A patent/JPH07505680A/en active Pending
-
1997
- 1997-11-28 US US08/980,403 patent/US6099664A/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| EP0632845A1 (en) | 1995-01-11 |
| GB2274467A (en) | 1994-07-27 |
| ZA94279B (en) | 1994-10-06 |
| JPH07505680A (en) | 1995-06-22 |
| GB9301458D0 (en) | 1993-03-17 |
| WO1994017219A1 (en) | 1994-08-04 |
| US6099664A (en) | 2000-08-08 |
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Legal Events
| Date | Code | Title | Description |
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| FZDE | Discontinued |