Influence of Si content and cooling rates on the size of SDAS and the latent heat released in Al-Si(5-11)-Cu1 alloys

Abstract

The latent heat of solidification of any alloy depends on the chemistry and the microstructure developed during solidification process. Effects of chemistry on the release of the latent heat during solidification and influence of the cooling rate on the size of the Secondary Dendrite Arm Spacing (SDAS) of the Al-Si-Cu series of aluminium alloys for the following levels of silicon: 5, 7, 9 and to 11 wt. % Si, have been analysed. The solidification process, fraction solid analysis and latent heat release measured by the Differential Scanning Calorimeter (DSC) apparatus has been studied using cooling curves at different cooling rates ranging from 6, 10 and 50 °C/minute. The findings based on experimental results and their analysis indicate that increase in the Si content of the investigated alloys Al-Si(5-11)Cu1, shift the characteristic temperatures towards lower values and have considerable effect on the fraction solid and the amount of released latent heat. The effect of the cooling rates is not so significant.