Improvement of the tensile strength of Al18B4O33w/Al composite at elevated temperatures by change of interfacial state

In general, it is very difficult to obtain obviously reinforced effect in discontinuously reinforced aluminum matrix composites at the temperature above 400 °C. In the present study, we report an effective method to improve the high-temperature tensile strength of Al₁₈B₄O₃₃w/Al composite by change of interfacial state. The pure aluminum matrix composites reinforced by Al₁₈B₄O₃₃w with different ZnAl₂O₄ coating contents were fabricated by squeeze casting. The results indicate that ZnAl₂O₄ coating of the whiskers can effectively improve the high-temperature tensile strength of Al₁₈B₄O₃₃w/Al composite, although the tensile strength of the composite decreases with increasing the tensile temperature. On the basis of fractograph analysis, the fracture mechanism of the composites at elevated temperatures was investigated.