Impression creep characterization of cast Al-7Si-0.3Mg alloy

The creep behavior of the as cast A356 (Al-7Si-0.3Mg) alloy is investigated by the impression creep test with a flat-ended cylindrical punch over a wide range of stress between 280 and 630 MPa and at the temperature range of 493 to 553 K. The tilt casting method is used to fabricate the cast A356 alloy. The microstructure of the alloy is characterized by the dendritic primary -Al, the eutectic Si phase and the iron-rich intermetallics ( -AlFeSi and β-AlFeSi). The stress exponent is found to be in the range of 6.1 to 7.6 and the activation energy is determined in the range of 134 to 152 kJ mol−1. It is found that the self-diffusion climb controlled creep is the operative creep mechanism. No evidence of the threshold stress is observed for the present alloy.