Effect of alloying elements on surface temperature field of aluminum piston in diesel engine

For three kinds of Aluminum-Silicon (Al-Si) alloy piston materials with different alloying element contents, the parameters such as thermal diffusion coefficient, specific heat capacity and thermal conductivity were measured, and the effects of Cu and Ni on the thermal properties of the materials were studied. Under the same processing conditions, three kinds of engine aluminum alloy pistons of different materials were manufactured. The piston surface temperature under the rated working condition of the diesel engine was measured by the hardness plug temperature calibration method. The distribution of piston surface temperature field was simulated by ANSYS finite element analysis, and the surface temperature analysis results of key parts of the piston were obtained. The results show that the finite element simulation results of piston surface temperature field are consistent with the temperature measurement results of hardness plug test, and the temperature change of key specific locations of piston possesses the similar trend. The thermal conductivity of aluminum alloy piston material increases with the increase of temperature. There is an obvious temperature gradient from the piston head to the piston skirt. High thermal conductivity can reduce the surface temperature of the piston head. The addition of alloying elements such as Cu and Ni will reduce the thermal conductivity of aluminum alloy materials and increase the surface temperature of piston. Therefore, proper controlling of the content of alloying elements can control the heat resistance and high temperature performance of piston materials.