Mechanical properties and thermal stability of ZnAl2O4-coated aluminum borate whiskers reinforced 2024Al composite

ZnAl2O4-coated aluminum borate whiskers reinforced 2024Al composite was fabricated by squeeze casting. Interfacial microstructures and tensile properties of the composite were investigated. The results show that ZnAl2O4 coating of the whiskers can improve the wettability of the whiskers by molten aluminum during squeeze casting, resulting in the increase of tensile properties of the composite. During thermal exposure, ZnAl2O4 at the interface can effectively hinder harmful interfacial reactions, resulting in the improvement of thermal stability of the composite at high temperatures. Fracture mechanisms of the composite in as-cast and after thermal exposure were also investigated.