Aluminium matrix hybrid composite materials reinforced with carbides and intermetallics

Abstract

Composite materials based on aluminum, reinforced withparticles of titanium carbide and intermetallic compounds of titanium aluminide, are made by casting technology. Investigations of the structure, mechanical and tribotechnical characteristics of the manufactured composite materials have been carried out. It is shown that the reinforcement of an aluminum matrix with TiC particles, or intermetallic phases of Al3Ti, formed by introducing reactive titanium powders into the melt, is an effective way to increase the tribotechnical characteristics. It has been established that the reinforcement of the aluminum matrix with TiC particles has a greater effect on the reduction of the friction coefficient and the wear rate, in comparison with the reinforcement with intermetallic phases Al3Ti, despite the higher volume fraction of the latter. It has been determined that the greatest wear resistance is provided by hybrid reinforcing of an aluminum matrix with TiC particles and intermetallic phases. The additional introduction of stronger TiC particles leads to a decrease in the load on the Al3Ti intermetallics, thereby preventing their destruction under the action of high external loads. In addition, the presence of a larger number of reinforcing phases in hybrid composite materials than in other composite materials samples provides not only a decrease in the load on each reinforcing particle separately, but also a decrease in the fraction of the matrix in the friction surface, thereby expanding the range of triboloading.