Metal matrix compositeA metal matrix composite is a type of metal material that is reinforced with another material which may be a ceramic material or possibly another metal.
Carbide drill bits are an example of a metal matrix composite. They are often made from a soft cobalt matrix with tough tungsten carbide particles inside.
Some tank armors may be made from metal matrix composites, probably steel reinforced with boron nitride. Boron nitride is a good reinforcement for steel because it is very stiff and it does not dissolve in molten steel.