a metal-matrix composite
Swap the soft plastic matrix for a metal, usually a light one like aluminum, magnesium, or titanium, reinforced with ceramic particles, whiskers, or fibers (silicon carbide, alumina, carbon). You get a metal that is stiffer, harder-wearing, and more heat-tolerant than the base alloy.
Reinforcing aluminum with about 10 to 30 percent silicon-carbide particles can raise stiffness from about 70 GPa toward 100 GPa or more, cut thermal expansion, and boost wear resistance, while keeping metal's conductivity and a higher service temperature (about 300 to 500 degrees C) than any polymer matrix. MMCs are made by casting the metal around particles, by powder metallurgy, or by infiltration.
MMCs shine where a polymer matrix cannot take the heat or where you need a metal's conductivity and toughness: engine pistons, brake rotors, spacecraft structures, and electronic heat spreaders (where low, tuned thermal expansion matters). The honest downsides: they are expensive, harder to machine (the ceramic wrecks tools), and can suffer chemical reaction at the fiber-metal interface at processing temperature.
Some high-performance brake discs and engine components use SiC-particle-reinforced aluminum: lighter than cast iron, stiffer and more wear-resistant than plain aluminum, and able to run hot.
A metal made stiffer and more wear-resistant, still limited by the metal's melting point.
An MMC's ceiling is still the metal's: reinforcement raises stiffness and wear resistance and cuts expansion, but the matrix melting point and oxidation still cap the service temperature, and machining the abrasive result is a real cost.