Effects of squeeze casting parameters on density, macrostructure and hardness of LM13 alloy

In this research the effects of applied pressure, melt and die temperatures on the density, macrostructure and hardness of squeeze cast LM13 alloy were investigated. The results showed that the density of the samples decreased with application of a 20 MPa external pressure but it increased steadily for higher applied pressures up to about 106 MPa after which it became almost constant. Increasing the applied pressure resulted in smaller grain size and improved hardness. A decrease in the melt or die temperature rendered similar effects on the macrostructure and hardness of the samples. The results were explained based on the changes in nucleation rate, cooling rate, and operation of feeding mechanisms brought about by the application of pressure during solidification.