Methods of forming erosion-resistant composites, methods of using the same, and earth-boring tools utilizing the same in internal passageways

A method of applying hardfacing to a surface of an earth-boring tool, comprising:

• mixing a plurality of hard particles, a plurality of metal matrix particles, a polymer material, and a liquid solvent to form a paste;
• spreading the paste over a surface of a substrate to form a layer of the paste;
• removing the liquid solvent from the layer of the paste to form an at least substantially solid film comprising the plurality of hard particles, the plurality of metal matrix particles, and the polymer material;
• removing the at least substantially solid film from the surface of the substrate;
• applying the at least substantially solid film to a surface of a body of an earth-boring tool;
• heating the body of the earth-boring tool to a first temperature while the at least substantially solid film is on the surface thereof and removing the polymer material from the body of the earth-boring tool;
• and
• heating the body of the earth-boring tool to a second temperature higher than the first temperature and sintering at least the plurality of metal matrix particles to form a layer of hardfacing material on the surface of the body of the earth-boring tool comprising the plurality of hard particles dispersed throughout a metal matrix phase formed from the plurality of metal matrix particles.