Preparation and characteristics of al matrix composites reinforced with ZnWO₄ coated (WO₃p + ABOw) hybrid reinforcements

In this article, a ZnWO₄ coating was prepared successfully on the surfaces of WO₃ particulates and Al₁₈B ₄O₃₃ whiskers by a chemical precipitation method. Then the Al matrix composite with coated reinforcements was fabricated by a squeeze casting technique. Scanning electronic microscope analysis shows that a thin coating is coated on the surfaces of reinforcements. Differential thermal analysis and x-ray diffraction (XRD) results show that the Zn(OH)₂ decomposes at 248 C and that the ZnWO₄ is produced by reaction WO₃ with ZnO at 716 C. Transmission electronic microscope and XRD analysis show that the coating of ZnWO₄ is effective to prevent interfacial reaction between the WO₃ particle and the Al matrix. The mechanical property testing shows that the ultimate tensile strength, elastic modulus, and elongation of the hybrid composites with coated reinforcements are improved greatly by introduction of ZnWO₄ coating.