Metal borides and uses thereof

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 WB4.