Non-Equilibrium Solidification Calculation and Microstructure Analysis of Al-Si-Cu-Mg-Ni High-Power Density Piston Aluminum Alloy

Abstract

Taking M142 high power density piston alloy as the research object, using thermo Calc thermodynamic calculation. The solidification path of the alloy system is calculated in the composition range of Cu (3.5% - 6.0wt%), Mg (0.5% - 1.2wt%), Si (11% - 14wt%) and Ni (2.1% - 3.0wt%). The microstructure formation laws of Cu, Mg and Ni elements were obtained. And the relationship between residual structure and temperature and composition in different states and stages. Analysis of alloy element pairs δ Phase (Al3CuNi) γ Phase (Al7Cu4Ni) and other main strengthening phases are analyzed and evaluated comprehensively. Based on the calculation of the solidification path of the alloy, the microstructure of the alloy is optimized, especially the multi eutectic and peritectic structure platform. The microstructure content, composition and temperature precipitation space are comprehensively designed and calculated, so as to optimize the process parameters such as the best composition, temperature and pressure of the alloy.