Metal matrix alloys

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.