Disclosed are heat resistant aluminum alloy powders and alloys including Ni, Si, either at least one of Fe and Zr or at least one of Zr and Ti. For instance, the alloy powders or alloys consist essentially of Ni in an amount of from 5.7 to 20% by weight, Si in an amount of from 0.2 to 25% by weight, at least one of Fe in an amount of from 0.6 to 8.0% by weight and Cu in an amount of from 0.6 to 5.0% by weight, and the balance of Al. The alloy powders or alloys are optimum for a matrix of heat and wear resistant aluminum alloy-based composite materials including at least one of nitride particles and boride particles in an amount of 0. 5 to 10% by weight with respect to the whole composite material taken as 100% by weight. The alloy powders, alloys and composite materials are satisfactory applicable to the component parts of the recent automobile engines which should produce a high output.