Mechanical properties and thermal stability of ZnAl₂O ₄-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.