Silicon particle damage in a thixocast a356 aluminium alloy

Abstract

The thixocast A356 aluminium alloy shows high mechanical properties if compared to those of the same alloy obtained by traditional foundry methods. This improvement is due to the fine and homogeneous globular microstructure that is obtained by thixocasting; traditional heat treatments are always possible. In the present study, samples of A356 thixocast aluminium bars have been solution treated and aged.

The precipitation hardening has been monitored by hardness and electrical conductivity measurements. Tensile tests have been performed on heat-treated samples and the importance of silicon particles in the fracture process has been put in evidence.