Metal borides and uses thereof
Disclosed herein are compounds, methods, and tools which comprise tungsten borides and mixed transition metal borides.
1 . A method of preparing a composite matrix method comprising:
i) mixing a source of tungsten (W) and a source of boron (B) to generate a mixture, wherein the ratio of B to W is less than 12 equivalents of B to 1 equivalent of W;
ii) transferring the mixture to a reaction vessel, wherein the reaction vessel comprises a liner, wherein the liner comprises hexagonal Boron Nitride (h-BN), molybdenum, tungsten, niobium, or tantalum; and
iii) heating the mixture to sufficiently induce a reaction between W and B to generate the composite matrix, wherein the composite matrix comprises WB 4 .
2 . The method of claim 1 , wherein the liner comprises molybdenum, tungsten, niobium, or tantalum.
3 . The method of claim 1 , wherein the liner comprises h-BN, molybdenum, or tungsten.
4 . The method of claim 1 , wherein the liner comprises h-BN.
5 . The method of claim 1 , wherein the reaction vessel is a carbon crucible.
6 . The method of claim 1 , wherein the reaction vessel is a non-carbon container.
7 . The method of claim 1 , wherein the composite matrix of WB 4 is formed with a W to B ratio of between 1:4.5 and 1:11.6.
8 . The method of claim 7 , wherein the density of the composite matrix of WB 4 is between about 5.15 g/cm 3 and 8.46 g/cm 3 .
9 . The method of claim 1 , wherein the composite matrix of WB 4 is formed with a W to B ratio of between 1:9 and 1:10.5.
10 . The method of claim 9 , wherein the density of the composite matrix of WB 4 is between about 5.44 g/cm 3 and 6.12 g/cm 3 .
11 . The method of claim 1 , wherein the mixture is heated by conventional furnace heated by metal coils, conventional furnace heated by combustion, electrical arc furnace, induction furnace, spark plasma sintering, or hot press.
12 . The method of claim 1 , wherein the mixture is heated by induction furnace or spark plasma sinter.
13 . The method of claim 1 , wherein the composite matrix of WB 4 comprises crystallites that are less than 10, 50, of 100 micrometer in size.
14 . The method of claim 1 , wherein the composite matrix of WB 4 comprises crystallites are from about 1 to 100 micrometers in size.
15 . The method of claim 1 , wherein the mixture is heated for about 15 minutes or more.
16 . The method of claim 1 , wherein the mixture is heated for about 15 to 360 minutes.
17 . The method of claim 1 , wherein the mixture is heated from 1500° C. to 1800° C.
18 . The method of claim 17 , wherein the mixture is heated from 1600° C. to 1700° C.
19 . The method of claim 1 , wherein the mixture is heated with a rate of 1° C. per minute to 50° C. per minute.
20 . The method of claim 19 , wherein the mixture is heated with the rate of 10-20° C. per minute.