Characterization of tib2 particle reinforced aluminum alloy matrix composites produced by powder metallurgy technique

Composite materials have gained a special importance by means of the developing technology in industrial areas such as military, space, aviation, automotive and marine. Al-alloy-based composites, in which different reinforcement materials are used, have an important potential in many areas due to having their high strength and wear resistance as well as their lightness. In this study, the microstructure, mechanical and erosive wear properties of the pure Al and Al alloy (Al-Zn-Cu-Mg) composite samples, which were prepared by powder metallurgy method and included TiB2 ceramic particle reinforcement at the different proportions, were investigated under different heat treatment conditions. The studies, which were started by determining the properties of the powders used, were continued with the investigation of the compressibility properties of the powder mixtures by applying different compression pressures up to 800 MPa. Then, the compressibility data of composite powders were evaluated by means of linear compressibility equations. Following these processes, the composite samples were produced by pressing at 316 MPa and sintering at 590 °C. After that, annealing, natural aging and artificial aging at 100, 120 and 140 °C were applied to the composite samples. After the heat treatments were completed, the microstructure properties of the samples were investigated with the help of SEM, EDS, analytical mapping and XRD. Furthermore, the hardness changes of the samples were investigated after the aging heat treatments and time-dependent aging curves were obtained. Finally, three point bending and erosive wear tests were carried out to see the effects of the microstructure of matrix, reinforcement volume ratio and the heat treatment on the mechanical and erosive wear properties of the composite specimens. According to the experimental results, it was determined that the highest hardness values were reached by means of the artificial aging process performed at 120 °C for all samples at ~ 11th hour. While the highest transverse rupture strength value was recorded for the artificially aged aluminum alloy, the annealed pure aluminum samples showed the best performance in the erosive wear tests. Besides, it had been observed that transverse rupture strength and wear resistance decreased with the increase of TiB2 particle amount in both matrix types.