Effect of interfacial Bi2O3 coating on compressive deformation behavior of aluminum borate whisker-reinforced aluminum composite at elevated temperature

A pure aluminum matrix composite reinforced by aluminum borate whisker with Bi2O3 coating was fabricated by squeeze casting method. During fabrication, there occurred an interfacial reaction between Bi2O3 coating and Al matrix, accompanying the formation of metallic bismuth on the interface. The compressive deformation results show that the existing bismuth coating on the interface is beneficial to the compressive deformation of composite thus decreases the maximum compressive flow stress and the probability of whisker fracture during compressive deformation at elevated temperature. The apparent activation energy of the composite with Bi2O3 coating is much larger than that of the composite without Bi2O3 coating at 220–320 °C. However, both of these two composites present the comparable apparent activation energy at 400–500 °C.