CA1090523A - Abrasion resistant iron-nickel bonded tungsten carbide - Google Patents
Abrasion resistant iron-nickel bonded tungsten carbideInfo
- Publication number
- CA1090523A CA1090523A CA273,333A CA273333A CA1090523A CA 1090523 A CA1090523 A CA 1090523A CA 273333 A CA273333 A CA 273333A CA 1090523 A CA1090523 A CA 1090523A
- Authority
- CA
- Canada
- Prior art keywords
- powder
- tungsten carbide
- binder
- blended
- iron
- 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
- UONOETXJSWQNOL-UHFFFAOYSA-N Tungsten carbide Chemical compound [W+]#[C-] UONOETXJSWQNOL-UHFFFAOYSA-N 0.000 title claims abstract description 27
- 238000005299 abrasion Methods 0.000 title claims abstract description 19
- -1 iron-nickel Chemical group 0.000 title abstract description 8
- 239000000843 powder Substances 0.000 claims abstract description 41
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims abstract description 37
- 239000011230 binding agent Substances 0.000 claims abstract description 26
- OKTJSMMVPCPJKN-UHFFFAOYSA-N carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 23
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 23
- 239000000203 mixture Substances 0.000 claims abstract description 19
- 229910052759 nickel Inorganic materials 0.000 claims abstract description 17
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 15
- 229910052742 iron Inorganic materials 0.000 claims abstract description 9
- 229910002804 graphite Inorganic materials 0.000 claims abstract description 8
- 239000010439 graphite Substances 0.000 claims abstract description 8
- 230000002939 deleterious Effects 0.000 claims abstract description 5
- 238000005245 sintering Methods 0.000 claims abstract description 5
- 238000004519 manufacturing process Methods 0.000 claims abstract description 4
- GORXZVFEOLUTMI-UHFFFAOYSA-N methane;vanadium Chemical compound C.[V] GORXZVFEOLUTMI-UHFFFAOYSA-N 0.000 claims description 11
- 239000002245 particle Substances 0.000 claims description 6
- 229910045601 alloy Inorganic materials 0.000 claims description 5
- 239000000956 alloy Substances 0.000 claims description 5
- REDXJYDRNCIFBQ-UHFFFAOYSA-N aluminium(3+) Chemical class [Al+3] REDXJYDRNCIFBQ-UHFFFAOYSA-N 0.000 claims description 5
- 239000012071 phase Substances 0.000 claims description 5
- 230000001427 coherent Effects 0.000 claims description 3
- 239000007791 liquid phase Substances 0.000 claims description 3
- 229910001030 Iron–nickel alloy Inorganic materials 0.000 claims description 2
- 230000001747 exhibiting Effects 0.000 claims 1
- 239000000463 material Substances 0.000 abstract description 20
- 238000005296 abrasive Methods 0.000 abstract description 7
- UHOVQNZJYSORNB-UHFFFAOYSA-N benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 description 6
- 229910052803 cobalt Inorganic materials 0.000 description 6
- 239000002002 slurry Substances 0.000 description 5
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt Chemical group [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 3
- 239000010941 cobalt Substances 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- PNEYBMLMFCGWSK-UHFFFAOYSA-N al2o3 Chemical class [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 2
- 229910052739 hydrogen Inorganic materials 0.000 description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 2
- 239000001257 hydrogen Substances 0.000 description 2
- 239000012188 paraffin wax Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- 229910013379 TaC Inorganic materials 0.000 description 1
- 229910001566 austenite Inorganic materials 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 125000002915 carbonyl group Chemical group [*:2]C([*:1])=O 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000002301 combined Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005755 formation reaction Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 229910000734 martensite Inorganic materials 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 150000001247 metal acetylides Chemical class 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 230000000284 resting Effects 0.000 description 1
- 230000000717 retained Effects 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 230000002195 synergetic Effects 0.000 description 1
- 229910003468 tantalcarbide Inorganic materials 0.000 description 1
Classifications
-
- 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
- C22C29/02—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides based on carbides or carbonitrides
- C22C29/06—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides based on carbides or carbonitrides based on carbides, but not containing other metal compounds
- C22C29/067—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides based on carbides or carbonitrides based on carbides, but not containing other metal compounds comprising a particular metallic binder
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C1/00—Making alloys
- C22C1/04—Making alloys by powder metallurgy
- C22C1/05—Mixtures of metal powder with non-metallic powder
- C22C1/051—Making hard metals based on borides, carbides, nitrides, oxides or silicides; Preparation of the powder mixture used as the starting material
-
- 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
- B22F5/00—Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product
- B22F2005/001—Cutting tools, earth boring or grinding tool other than table ware
Abstract
ABRASION RESISTANT IRON-NICKEL
BONDED TUNGSTEN CARBIDE
ABSTRACT OF THE DISCLOSURE
Disclosed is a method of making tungsten carbide materials and the resulting product useful for cutting tools and other applications where a high persistance to abrasive wear is required. WC powder is blended with 0.1 to 1.5 wt% VC and a binder powder, in an amount (3 to 30 wt%) of the blend, the binder consisting essentially of 7.0 to 15 wt% Ni, and the remainder iron. The carbon content is adjusted to insure substantial absence of eta phase and deleterious amounts of graphite upon sinter-ing. The blend is screened, pressed into compacts and sintered at a temperature of 1400°C for a period of time of one hour.
BONDED TUNGSTEN CARBIDE
ABSTRACT OF THE DISCLOSURE
Disclosed is a method of making tungsten carbide materials and the resulting product useful for cutting tools and other applications where a high persistance to abrasive wear is required. WC powder is blended with 0.1 to 1.5 wt% VC and a binder powder, in an amount (3 to 30 wt%) of the blend, the binder consisting essentially of 7.0 to 15 wt% Ni, and the remainder iron. The carbon content is adjusted to insure substantial absence of eta phase and deleterious amounts of graphite upon sinter-ing. The blend is screened, pressed into compacts and sintered at a temperature of 1400°C for a period of time of one hour.
Description
The present invention relates to tungsten carbide products.
Cobalt-bonded tungsten carbide materials are well known for their resistance to abrasive wear; they are widely used because they combine this property with good strength and impact resistance. In 1968, it was shown by the inventors herein that iron-nickel bonded tungsten carbide has superior transverse rupture strength to the cobalt-bonded materials, provided certain conditions were observed and precautions were taken to prevent formation of a deleterious "eta" phase by control of carbon (see U.S. Patent No. 3,384,465). Conditions necessary to successfully produce high strength iron-nickel bonded WC
material were: the sintered WC grain size must be below 5 microns, and the nickel content of the binding metal should be between S and 40% by weight. However, these conditions and precautions are necessary but not sufficient to yield materials of optimal abrasive wear resistance.
In accordance with the present invention, there is provided a method of making iron-bonded tungsten carbide powder compacts comprising: (a) forming a powder mixture blend consisting of tungsten carbide powder, 0.1 to 1.5 wt%
vanadium carbide, and a binder powder constituting about 3 to 30 wt% of the mixture, the binder powder consisting essentially of 7.0 to 15 wt% nickel and ~he remainder iron;
(b) adding additional carbon in an excess amount of 0.2 to 1.0 wt% over and above the carbon required to satisfy stoichiometric WC; (c) homogenizing the blended powders;
(d) cold compacting the homogenized powder with sufficient pressure to form a coherent compact; and (e) liquid phase sintering the compacts at 1300 to 1500C for sufficient ~O905Z3 time to achieve a uniformly bonded microstructure.
The presence of the small amount of vanadium carbide powder and the adjustment of the carbon content of the powder mixture results in a hard sintered compact which is useful for cutting tools and other applications where a high resistance to abrasive wear is required while not sacrificing transverse rupture strength and impact resistance.
The present invention also provides a hard sintered compact consisting essentially of tungsten car-bide and 0.1 to 1.5 wt% vanadium carbide particles bonded by an alloy consisting essentially of 7 to 15 wt% nickel, and the remainder iron, carbon in the compact being adjusted to assure the substantial absence of an eta phase and a deleterious amount of graphite, substantially all of the grains of the ~intered tungsten carbide having a grain size of not over S microns.
The invention is described further, by way of illustration, with reference to the accompanying drawings, in which:
Figure 1 is a graphical illustration plotting the variation of abrasion resistance factor with the percent binder; several plots are illustrated, one of which repre-sents data generated employing the inventive teaching herein;
Figure 2 is a sectional view of an apparatus employed to determine abrasive resistance factor;
Figures 3 and 4 are micro-photographs of tungsten carbide material produced respectively with and without the addition of VC in accordance with the present invention;
and lO~OSZ3 Figure 5 is a graphical illustration of wear resis-tance factor as varied with the nickel content of the binder.
Abrasion resistance of cemented carbides is determined by a commonly used test approved by the cemented carbide Producers Association, procedure P-112. The test employs a suitable vessel 10, such as that shown in ~igure 2, which holds a wet abrasive in the form of an aluminum oxide slurry 11; an abrading wheel 12 is disposed partly immersed in the slurry. The wheel has mixing vanes 13 on each side to lift and swirl the slurry against the specimen 14. The steel wheel normally rotates in the center of the vessel at about a 100 r.p.m.; the direction of the rotation is as shown. A specimen holder 15 causes the specimen 14 to bear against the periphery of the wheel. The holder 15 is L-shaped and pivots about the apex 16. The specimen holder must be mounted so that there is no more than 0.002 inch side play occurring at the line of contact between the specimen and the wheel. The specimen is so placed that it is tangent to the wheel at about the centerline of the wheel. A 25 lb. weight 17 is attached to the end of lever arm 16a of holder 15. With a lever advantage of 2 to 1, a load of 50 lbs. is thereby applied at the specimen at the line of contact 18.
The procedure for the test is essentially as follows:
(al A sample is weight to the nearest 0.0001 gram. (b) The density is determined, (c) The specimen is placed on the holder, and inserted into the wear test machine. (d) The 25 lb. weight is released causing a load to be applied to the specimen causing it to bear against the wheel. (e) The bottom drain of the vessel is closed and 30 grains of - 3a -aluminum oxide (A1203), is poured into the vessel to within 1 inch of the center of the wheel. Water is added to the aluminum oxide in a ratio of 1 cc per 4 grams of grit.
When water has seeped into the abrasive grit, rotation of the wheel is - 3b -lO905Z3 started and run for 1300 revolutions (determined by means of a counter). The slurry is stirred to insure uniformity.
(g) The weight of the specimen is then weighed. The abrasion resistahce factor is computed by the formula:
Abrasion resistance (cm3? = ~eight loss in gms. x 105 factor (REV) 1300 REV x Density of Specimen As shown in Figure 5, wear resistance appears to be optimal for nickel contents in the range from 7 to 15% by weight of the binder. Plot 2 represents abrasion resistance for an as-sintered composition according to the invention herein; plot 20 is for the same composition which has been additionally subjected to a treatment at -196C. The Rockwell "A" hardness follows a similar trend (not shown), the hardest compositions falling within the same nickel range. Treatment at -19~C produces additional improvement in both properties, due to conversion of retained austenite in the binder to the harder martensite.
We have now found that iron-nickel bonded tungsten carbide materials will be superior to cobalt bonded materials in abrasion resistance and superior to iron-nickel bonded tungsten carbide materials by the employment of controlled amounts of vanadium carbide. The increase in abrasion resis-tance is best illustrated by reference to Figure 1 wherein a comparison is made between materials produced according to prior methods and materials produced according to the inventive method herein. Plot 1 represents a variation in the abrasion resistance with percent binder for a cobalt-bonded tungsten carbide material. Plot 2 is for tungsten carbide material employing an iron-nickel binder, the nickel representing 20%
of the binder. The lower factor values for each binder i ~0905Z3 percentage of plot 2 represent material subjected to a cold treatment at -196~C. Plot 3 represents an iron-nickel bonded tungsten carbide material employing 10~
nickel in the binder. Again the lowest factor values for each binder percentage of plot 3 represent material subjected to a cold treatment of -196C. Plot 4 represents a tungsten carbide material in accordance with the present invention wherein vanadium carbide has been added in an amount of up to 1~ by weight. Plot 3 particularly shows the effect on abrasion resistance factor keeping the nickel content of the binder at about 10%, and varying the binder content; plot 2 exhibits less desirable abrasion resistance factor which is directly related to the high nickel content. Plot 3 is superior to plot 1 containing a cobalt bonded material, irrespective of the binder content.
By deploying the same control limits as that for the material of plot 3, but additionally adding vanadium carbide, a synergistic effect in abrasion resistance factor was observed (see plot 4). Notably, the small vanadium carbide addition reduced the abrasion resistance factor to a value approximately 1/2 of that with no addition.
Of particular significance, insofar as the practical application of the material is concerned, is the fact that the improvement in abrasion resistance factor does not come at the expense of a loss in strength. Transverse rupture strength is approximately equal to that of the cobalt bonded composition of an equivalent binder content.
Several samples were prepared and tested to evaluate the present invention; the samples were tested for hardness and abrasion resistance. In each case the RA hardness value was at least 92 and the samples had a transverse ,~
rupture strength of at least 200,000 psi. The resulting data for six samples is shown in Table I below:
- 5a -Table I
Composition Treatment Abrasion Resistance Hardness Factor (10-5 cm3/Rev) (RA) 94-3/4% WC + 1/4% VC
+ 5% (Fe 10 Ni)-196C (twice) 0.52 94.0 97% WC + 3% Co ~Jone 2.09 92.6 89-1/2% WC + 1/2% VC
+ 10~ (Fe 10 Ni)-196C (twice) 1.31 93.75 92% WC + 4% TaC
+ 4% Co None 3.4~ 92.0 81-1/2% ~C + 1% VC
+ 17-1/2% (Fe 10 Ni) -196C (twice) 6.81 92.65 87% WC + 13% Co None - 15.8 89.2 The following procedure was used to produce the above samples. Tungsten carbide powder, less than 3 microns in average particle size and containing 6.1 weight percent com-bined carbon, was added to a stainless steel mill loaded with tungsten carbide-based balls, together with required amounts of hydrogen reduced electrolytic iron powder, carbonyl or electrolytic nickel powder, and spectroscopically pure graphite powder. Graphite powder or excess carbon was added or present in an amount of at least .2-1.0 wt. ~ over and above the amount required to satisfy stoichiometric WC; this completely inhibits eta phase (Fe3w3C). Sufficient benzene was added to cover the charge, which was then ball milled for four days. 2% paraffin was dissolved in the benzene and uni~ormly distri~uted throughout the slurry; the benzene was then completely evaporated. The dry powder was screened through a 20 mesh sieve and then pressed into segments at a pressure of 20,000 psi. The paraffin was removed by dewaxing at 750F (400C) under dry hydrogen or vacuum.
Specimens were sintered by heating under vacuum for 1 hour lO905Z3 at (2550-2600F) or about 1400C, while resting on graphite trays on which 100 mesh crystallites of tungsten carbide had been sprinkled.
Another typical composition which may be used is 74 wt% WC, 25 wt% Fe-Ni and 1.25 wt% VC.
Figures 3 and 4 demonstrate that the presence of the required amounts of VC do not significantly act as a grain refiner for the microstructure of the sintered compact. Figure 3 shows a sample under the electron microscope containing 95% WC, 5~ binder consisting of 10%
Ni and the remainder iron; no VC was employed. Figure 4 shows a sample having 94.75% WC, 5% binder containing 10%
Nickel and the remainder iron; .25~ VC is employed. There is little difference between the WC grain size in each figure. The magnification for each figure is 5012X.
B
Cobalt-bonded tungsten carbide materials are well known for their resistance to abrasive wear; they are widely used because they combine this property with good strength and impact resistance. In 1968, it was shown by the inventors herein that iron-nickel bonded tungsten carbide has superior transverse rupture strength to the cobalt-bonded materials, provided certain conditions were observed and precautions were taken to prevent formation of a deleterious "eta" phase by control of carbon (see U.S. Patent No. 3,384,465). Conditions necessary to successfully produce high strength iron-nickel bonded WC
material were: the sintered WC grain size must be below 5 microns, and the nickel content of the binding metal should be between S and 40% by weight. However, these conditions and precautions are necessary but not sufficient to yield materials of optimal abrasive wear resistance.
In accordance with the present invention, there is provided a method of making iron-bonded tungsten carbide powder compacts comprising: (a) forming a powder mixture blend consisting of tungsten carbide powder, 0.1 to 1.5 wt%
vanadium carbide, and a binder powder constituting about 3 to 30 wt% of the mixture, the binder powder consisting essentially of 7.0 to 15 wt% nickel and ~he remainder iron;
(b) adding additional carbon in an excess amount of 0.2 to 1.0 wt% over and above the carbon required to satisfy stoichiometric WC; (c) homogenizing the blended powders;
(d) cold compacting the homogenized powder with sufficient pressure to form a coherent compact; and (e) liquid phase sintering the compacts at 1300 to 1500C for sufficient ~O905Z3 time to achieve a uniformly bonded microstructure.
The presence of the small amount of vanadium carbide powder and the adjustment of the carbon content of the powder mixture results in a hard sintered compact which is useful for cutting tools and other applications where a high resistance to abrasive wear is required while not sacrificing transverse rupture strength and impact resistance.
The present invention also provides a hard sintered compact consisting essentially of tungsten car-bide and 0.1 to 1.5 wt% vanadium carbide particles bonded by an alloy consisting essentially of 7 to 15 wt% nickel, and the remainder iron, carbon in the compact being adjusted to assure the substantial absence of an eta phase and a deleterious amount of graphite, substantially all of the grains of the ~intered tungsten carbide having a grain size of not over S microns.
The invention is described further, by way of illustration, with reference to the accompanying drawings, in which:
Figure 1 is a graphical illustration plotting the variation of abrasion resistance factor with the percent binder; several plots are illustrated, one of which repre-sents data generated employing the inventive teaching herein;
Figure 2 is a sectional view of an apparatus employed to determine abrasive resistance factor;
Figures 3 and 4 are micro-photographs of tungsten carbide material produced respectively with and without the addition of VC in accordance with the present invention;
and lO~OSZ3 Figure 5 is a graphical illustration of wear resis-tance factor as varied with the nickel content of the binder.
Abrasion resistance of cemented carbides is determined by a commonly used test approved by the cemented carbide Producers Association, procedure P-112. The test employs a suitable vessel 10, such as that shown in ~igure 2, which holds a wet abrasive in the form of an aluminum oxide slurry 11; an abrading wheel 12 is disposed partly immersed in the slurry. The wheel has mixing vanes 13 on each side to lift and swirl the slurry against the specimen 14. The steel wheel normally rotates in the center of the vessel at about a 100 r.p.m.; the direction of the rotation is as shown. A specimen holder 15 causes the specimen 14 to bear against the periphery of the wheel. The holder 15 is L-shaped and pivots about the apex 16. The specimen holder must be mounted so that there is no more than 0.002 inch side play occurring at the line of contact between the specimen and the wheel. The specimen is so placed that it is tangent to the wheel at about the centerline of the wheel. A 25 lb. weight 17 is attached to the end of lever arm 16a of holder 15. With a lever advantage of 2 to 1, a load of 50 lbs. is thereby applied at the specimen at the line of contact 18.
The procedure for the test is essentially as follows:
(al A sample is weight to the nearest 0.0001 gram. (b) The density is determined, (c) The specimen is placed on the holder, and inserted into the wear test machine. (d) The 25 lb. weight is released causing a load to be applied to the specimen causing it to bear against the wheel. (e) The bottom drain of the vessel is closed and 30 grains of - 3a -aluminum oxide (A1203), is poured into the vessel to within 1 inch of the center of the wheel. Water is added to the aluminum oxide in a ratio of 1 cc per 4 grams of grit.
When water has seeped into the abrasive grit, rotation of the wheel is - 3b -lO905Z3 started and run for 1300 revolutions (determined by means of a counter). The slurry is stirred to insure uniformity.
(g) The weight of the specimen is then weighed. The abrasion resistahce factor is computed by the formula:
Abrasion resistance (cm3? = ~eight loss in gms. x 105 factor (REV) 1300 REV x Density of Specimen As shown in Figure 5, wear resistance appears to be optimal for nickel contents in the range from 7 to 15% by weight of the binder. Plot 2 represents abrasion resistance for an as-sintered composition according to the invention herein; plot 20 is for the same composition which has been additionally subjected to a treatment at -196C. The Rockwell "A" hardness follows a similar trend (not shown), the hardest compositions falling within the same nickel range. Treatment at -19~C produces additional improvement in both properties, due to conversion of retained austenite in the binder to the harder martensite.
We have now found that iron-nickel bonded tungsten carbide materials will be superior to cobalt bonded materials in abrasion resistance and superior to iron-nickel bonded tungsten carbide materials by the employment of controlled amounts of vanadium carbide. The increase in abrasion resis-tance is best illustrated by reference to Figure 1 wherein a comparison is made between materials produced according to prior methods and materials produced according to the inventive method herein. Plot 1 represents a variation in the abrasion resistance with percent binder for a cobalt-bonded tungsten carbide material. Plot 2 is for tungsten carbide material employing an iron-nickel binder, the nickel representing 20%
of the binder. The lower factor values for each binder i ~0905Z3 percentage of plot 2 represent material subjected to a cold treatment at -196~C. Plot 3 represents an iron-nickel bonded tungsten carbide material employing 10~
nickel in the binder. Again the lowest factor values for each binder percentage of plot 3 represent material subjected to a cold treatment of -196C. Plot 4 represents a tungsten carbide material in accordance with the present invention wherein vanadium carbide has been added in an amount of up to 1~ by weight. Plot 3 particularly shows the effect on abrasion resistance factor keeping the nickel content of the binder at about 10%, and varying the binder content; plot 2 exhibits less desirable abrasion resistance factor which is directly related to the high nickel content. Plot 3 is superior to plot 1 containing a cobalt bonded material, irrespective of the binder content.
By deploying the same control limits as that for the material of plot 3, but additionally adding vanadium carbide, a synergistic effect in abrasion resistance factor was observed (see plot 4). Notably, the small vanadium carbide addition reduced the abrasion resistance factor to a value approximately 1/2 of that with no addition.
Of particular significance, insofar as the practical application of the material is concerned, is the fact that the improvement in abrasion resistance factor does not come at the expense of a loss in strength. Transverse rupture strength is approximately equal to that of the cobalt bonded composition of an equivalent binder content.
Several samples were prepared and tested to evaluate the present invention; the samples were tested for hardness and abrasion resistance. In each case the RA hardness value was at least 92 and the samples had a transverse ,~
rupture strength of at least 200,000 psi. The resulting data for six samples is shown in Table I below:
- 5a -Table I
Composition Treatment Abrasion Resistance Hardness Factor (10-5 cm3/Rev) (RA) 94-3/4% WC + 1/4% VC
+ 5% (Fe 10 Ni)-196C (twice) 0.52 94.0 97% WC + 3% Co ~Jone 2.09 92.6 89-1/2% WC + 1/2% VC
+ 10~ (Fe 10 Ni)-196C (twice) 1.31 93.75 92% WC + 4% TaC
+ 4% Co None 3.4~ 92.0 81-1/2% ~C + 1% VC
+ 17-1/2% (Fe 10 Ni) -196C (twice) 6.81 92.65 87% WC + 13% Co None - 15.8 89.2 The following procedure was used to produce the above samples. Tungsten carbide powder, less than 3 microns in average particle size and containing 6.1 weight percent com-bined carbon, was added to a stainless steel mill loaded with tungsten carbide-based balls, together with required amounts of hydrogen reduced electrolytic iron powder, carbonyl or electrolytic nickel powder, and spectroscopically pure graphite powder. Graphite powder or excess carbon was added or present in an amount of at least .2-1.0 wt. ~ over and above the amount required to satisfy stoichiometric WC; this completely inhibits eta phase (Fe3w3C). Sufficient benzene was added to cover the charge, which was then ball milled for four days. 2% paraffin was dissolved in the benzene and uni~ormly distri~uted throughout the slurry; the benzene was then completely evaporated. The dry powder was screened through a 20 mesh sieve and then pressed into segments at a pressure of 20,000 psi. The paraffin was removed by dewaxing at 750F (400C) under dry hydrogen or vacuum.
Specimens were sintered by heating under vacuum for 1 hour lO905Z3 at (2550-2600F) or about 1400C, while resting on graphite trays on which 100 mesh crystallites of tungsten carbide had been sprinkled.
Another typical composition which may be used is 74 wt% WC, 25 wt% Fe-Ni and 1.25 wt% VC.
Figures 3 and 4 demonstrate that the presence of the required amounts of VC do not significantly act as a grain refiner for the microstructure of the sintered compact. Figure 3 shows a sample under the electron microscope containing 95% WC, 5~ binder consisting of 10%
Ni and the remainder iron; no VC was employed. Figure 4 shows a sample having 94.75% WC, 5% binder containing 10%
Nickel and the remainder iron; .25~ VC is employed. There is little difference between the WC grain size in each figure. The magnification for each figure is 5012X.
B
Claims (12)
1. A method of making iron-bonded tungsten carbide powder compacts comprising:
(a) forming a powder mixture blend consisting of tungsten carbide powder, 0.1 to 1.5 wt% vanadium carbide, and a binder powder constituting about 3 to 30 wt% of the mixture, said binder powder consisting essentially of 7.0 to 15 wt% nickel and the remainder iron;
(b) adding additional carbon in an excess amount of 0.2 to 1.0 wt% over and above the carbon required to satisfy stoichiometric WC;
(c) homogenizing said blended powders;
(d) cold compacting said homogenized powder with sufficient pressure to form a coherent compact; and (e) liquid phase sintering said compacts at 1300 to 1500°C for sufficient time to achieve a uniformly bonded microstructure.
(a) forming a powder mixture blend consisting of tungsten carbide powder, 0.1 to 1.5 wt% vanadium carbide, and a binder powder constituting about 3 to 30 wt% of the mixture, said binder powder consisting essentially of 7.0 to 15 wt% nickel and the remainder iron;
(b) adding additional carbon in an excess amount of 0.2 to 1.0 wt% over and above the carbon required to satisfy stoichiometric WC;
(c) homogenizing said blended powders;
(d) cold compacting said homogenized powder with sufficient pressure to form a coherent compact; and (e) liquid phase sintering said compacts at 1300 to 1500°C for sufficient time to achieve a uniformly bonded microstructure.
2. The method of claim 1, wherein the sintered compacts are additionally subjected to a temperature of about -196°C .
3. The method of claim 1, wherein the blended powder consists of 94.75 wt% WC/5 wt% (FelONi)/0.25 wt% VC.
4. The method of claim 1, wherein said blended powder consists of 89.5 wt% WC/10 wt% (FelONi)/0.5 wt% VC.
5. The method of claim 1, wherein said blended powder consists of 8.15 wt% WC/17.5 wt% (FelONi)/1.0 wt% VC.
6. The method of claim 1, wherein the blended powder consists of 74 wt% WC/25 wt% (Fe-Ni)/1.25 wt% VC.
7. The method of claim 1, wherein said blended powder is comprised of separate tungsten carbide powder containing about 6% by weight combined carbon, electrolytic iron powder, nickel powder, and spectroscopically pure graphite powder.
8. A method of making iron bonded tungsten carbide compacts exhibiting high abrasion resistance, high trans-verse rupture strength and good impact resistance, the method comprising:
(a) preparing a powder mixture blend of tungsten carbide powder having a particle size of less than 3 microns, 0.1 to 1.5 wt% of vanadium carbide powder, and a binding alloy powder having a particle size less than -325 mesh, said binding alloy powder constituting about 3 to 30 wt% of the mixture and consisting essentially of 85 to 93 wt% iron, 7.0 to 15 wt% nickel, (b) adjusting the carbon content of said blend to insure substantial absence of an eta phase (Fe3W3C) and of deleterious amounts of graphite upon sintering by adding additional carbon in an excess amount of 0.2 to 1.0 wt% over and above the carbon required to satisfy stoichiometric WC, (c) homogenizing the blended and adjusted powders, (d) screening said homogenized powders to a particle size of about 20 mesh, (e) cold compacting said blended and sized powders with sufficient pressure to form a coherent compact, and (f) liquid phase sintering said compacts at a temperature of about 1400°C for a period of time of about 1 hour under an inert atmosphere to achieve a uniformly bonded microstructure.
(a) preparing a powder mixture blend of tungsten carbide powder having a particle size of less than 3 microns, 0.1 to 1.5 wt% of vanadium carbide powder, and a binding alloy powder having a particle size less than -325 mesh, said binding alloy powder constituting about 3 to 30 wt% of the mixture and consisting essentially of 85 to 93 wt% iron, 7.0 to 15 wt% nickel, (b) adjusting the carbon content of said blend to insure substantial absence of an eta phase (Fe3W3C) and of deleterious amounts of graphite upon sintering by adding additional carbon in an excess amount of 0.2 to 1.0 wt% over and above the carbon required to satisfy stoichiometric WC, (c) homogenizing the blended and adjusted powders, (d) screening said homogenized powders to a particle size of about 20 mesh, (e) cold compacting said blended and sized powders with sufficient pressure to form a coherent compact, and (f) liquid phase sintering said compacts at a temperature of about 1400°C for a period of time of about 1 hour under an inert atmosphere to achieve a uniformly bonded microstructure.
9. A hard sintered compact consisting essentially of tungsten carbide and 0.1 to 1.5 wt% vanadium carbide particles bonded by an alloy consisting essentially of 7 to 15 wt% nickel, and the remainder iron, carbon in the compact being adjusted to assure the substantial absence of an eta phase and a deleterious amount of graphite, substantially all of the grains of the sintered tungsten carbide having a grain size of not over 5 microns.
10. The sintered compact of claim 9, which exhibits a transverse rupture strength of at least 200,000 psi and an RA hardness value of at least 92.
11. The sintered compact of claim 9, which exhibits an abrasion resistance factor of no greater than 0.6 x 10-5cm3/rev. for 5% binder, 1.35 x 10-5cm3/rev. for 10%
binder, and 7.0 x 10-5cm3/rev. for 17.5% binder.
binder, and 7.0 x 10-5cm3/rev. for 17.5% binder.
12. The sintered compact of claim 9, wherein increasing amounts of vanadium carbide are present in said compact in proportion to increasing amounts of the binder alloy.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US68062976A | 1976-04-26 | 1976-04-26 | |
| US680,629 | 1976-04-26 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1090523A true CA1090523A (en) | 1980-12-02 |
Family
ID=24731862
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA273,333A Expired CA1090523A (en) | 1976-04-26 | 1977-03-07 | Abrasion resistant iron-nickel bonded tungsten carbide |
Country Status (3)
| Country | Link |
|---|---|
| CA (1) | CA1090523A (en) |
| DE (1) | DE2718594C2 (en) |
| GB (1) | GB1572524A (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| ZA818744B (en) * | 1982-02-01 | 1982-12-30 | Gec | Cemented carbide compositions |
| US5281260A (en) * | 1992-02-28 | 1994-01-25 | Baker Hughes Incorporated | High-strength tungsten carbide material for use in earth-boring bits |
| US5841045A (en) * | 1995-08-23 | 1998-11-24 | Nanodyne Incorporated | Cemented carbide articles and master alloy composition |
| EP1453627A4 (en) * | 2001-12-05 | 2006-04-12 | Baker Hughes Inc | Consolidated hard materials, methods of manufacture, and applications |
| CN114603146A (en) * | 2022-01-31 | 2022-06-10 | 北京科技大学 | Preparation method of homogenized large-size tungsten crucible |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3384465A (en) * | 1967-06-22 | 1968-05-21 | Ford Motor Co | Iron bonded tungsten carbide |
-
1977
- 1977-03-07 CA CA273,333A patent/CA1090523A/en not_active Expired
- 1977-04-05 GB GB1421677A patent/GB1572524A/en not_active Expired
- 1977-04-26 DE DE19772718594 patent/DE2718594C2/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| GB1572524A (en) | 1980-07-30 |
| DE2718594C2 (en) | 1983-12-29 |
| DE2718594A1 (en) | 1977-11-03 |
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