Longhui Yao

Design and tensile properties of aluminum borate whiskers reinforced aluminum composite with low whisker volume fraction

Abstract ZnO was firstly coated on the surface of aluminum borate whiskers (ABOw) by sol–gel. Then, ZnO-coated ABOw was added into soybean slurry to make a preform with low volume fraction and the preform was sintered at high temperatures to obtain a sufficient strength. ABOw reinforced aluminum composite (ABOw/Al) was fabricated by squeeze casting. Interfacial microstructures, tensile properties, and fracture mechanisms of the ABOw/Al composite were investigated. The results show that the coating of ABOw and the addition of soybean sacrificial filler can effectively decrease the volume fraction of whiskers in the composite. The ultimate tensile strength of composite has not changed much with the decrease of whiskers volume fraction in the composite. However, the elongation to fracture of the composite evidently increases and it can reach 11.1% at room temperature.

Effect of ZnAl2O4 coating on the compressive behaviors of aluminum borate whiskers-reinforced aluminum composites at elevated temperatures

Abstract Aluminum borate whiskers (ABOw) with or without ZnAl2O4 coating reinforced pure aluminum composites (ABOw/Al, ABOw/ZnAl2O4/Al) were fabricated by squeeze casting. The effects of ZnAl2O4 coating on the compressive behaviors, microstructures, and matrix textures of the composites were investigated at different temperatures and strain rates. The results indicate that the maximum compressive flow stress of the composites almost linearly decreases with the increase in temperature. The maximum compressive flow stress of ABOw/ZnAl2O4/Al composite is higher than that of ABOw/Al composite at the same temperature when the strain rate is larger, however, it is reversed when the strain rate is smaller. It is more serious for the fracture of whiskers in ABOw/ZnAl2O4/Al composite than that in ABOw/Al composite at the high compressive strain rate. However, the average length of whiskers in ABOw/ZnAl2O4/Al composite is larger than that in ABOw/Al composite at the low compressive strain rate. The strong matrix texture in ABOw/ZnAl2O4/Al composite appears at the high compressive strain rate, however, it is observed in ABOw/Al composite at the low compressive strain rate.