Composites are fabricated from Zn-22Al base superplastic pre-alloy powder mixed individually with K₂O-6TiO₂, Al₂O₃, ZrO₂ and SiC powders (or whiskers) to improve mechanical strength of the Zn-22Al base powder compacts. Effects of mixing ratio, mixing time and forming temperature on strength of the composites are investigated and densification behaviour of the composites is compared to that of a magnetic composite material.
It is found that the Al₂O₃ powder has good suitability for the Zn-22Al base superplastic powder and the moderate mixing ratio of the Al₂O₃ powder is 15wt%. Maximum ring crushing strength of the composites made by Zn-22Al-1.OCu-0.03Mg superplastic powder mixed with the Al₂O₃ powder of 15wt% reaches 655MPa under a condition of the forming temperature of 420°C.