Effects of Alloying Elements and Temperature on Thermodynamic State and Microstructure of Piston Aluminum Alloy

Abstract

Taking high power density M142 piston aluminum alloy as the main research object, this paper studies the changes of element contents such as Si, Fe and Cu, as well as the effects on the precipitation strengthening phase sequence, type and phase transformation. Based on the phase diagram and thermodynamic calculation results of multicomponent alloys between different elements, the phase transformation in the solidification process of the alloy, as well as the temperature and composition window of each phase transformation were studied. Especially in alloys ε Phase (Al3Ni), δ Phase (Al3CuNi), and γ phase (Al7Cu4Ni). The thermodynamic conditions for the formation of nickel rich heat-resistant phases. At the same time, the effects of the contents of Cu, Fe and other elements on the solidification structure were studied. The optimum composition, temperature, pressure and other process parameters of the alloy were optimized. At the same time, it is analyzed and verified in combination with relevant metallographic photos to deeply understand and master the composition design and preparation process of the alloy.