Improvement of the tensile strength of Al_(18)B_4O_(33)w/Al composite at elevated temperatures by change of interfacial state

摘要

In general, it is very difficult to obtain obviously reinforced effect in discontinuously reinforced aluminum matrix composites at the temperature above 400℃. In the present study, we report an effective method to improve the high-temperature tensile strength of Al_(18)B_4O_(33)w/Al composite by change of interfacial state. The pure aluminum matrix composites reinforced by Al_(18)B_4O_(33)w with different ZnAl_2O_4 coating contents were fabricated by squeeze casting. The results indicate that ZnAl_2O_4 coating of the whiskers can effectively improve the high-temperature tensile strength of Al_(18)B_4O_(33)w/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.