Effects of thermal–mechanical cycling on microstructure and tensile properties of B/Al composite

The tensile properties of as-fabricated B/Al composites and after thermal–mechanical cycling (TMC) were studied. The results indicate that the Young's modulus of the B/Al composite decreases significantly with increasing the cycles, and the external stress enhances this tendency. The external stress during the TMC also exerts influence on the tensile strengths of the composite. The mechanism of this effect is analyzed in this study. The microstructural observations indicate that TMC induces firstly the generation and then the recovery effects of dislocations in the aluminum matrix. The interfaces in the B/Al composite change from the strongly bonded toward the appropriately bonded, then to the weakly bonded ones with increasing the cycle number. TMC is a new technique of improving the ultimate tensile strength of B/Al composite.