Effect of Al۲O۳ content on mechanical properties of Al/Al۲O۳ functionally graded composite materials fabricated by powder metallurgy

In this research, the effect of Al۲O۳ content has been investigated on mechanical properties of Al/Al۲O۳ functionally graded composite materials (FGCMs), using a powder metallurgy manufacturing method. A four-layer FGCMs of Al/Al۲O۳ is fabricated with compositions of ۵ to ۴۰ wt.% Al۲O۳. The samples were cold pressed under ۶۲۰ MPa and then sintered at ۶۴۰ °C temperature for ۱h. The highest flexural strength was obtained on Al/Al۲O۳ FGCMs included compositions of ۵, ۱۵, ۲۵, ۳۵ wt.% Al۲O۳. When the Al۲O۳ content in the matrix layer increases, hardness value also increases. The hardness changed in range of ۱۴۰-۱۶۰ HV. The results showed that increasing Al۲O۳ in matrix layer lead to brittle fracture in Al/Al۲O۳ FGCMs.