Technology innovation of aluminum alloy rheo squeeze casting

In this paper, the rheo squeeze casting technology of 7075 aluminum alloy was studied, and the process parameters of rheo squeeze casting of 7075 aluminum alloy were obtained. The heat treatment process of 7075 alloy in rheo squeeze casting was studied. The microstructure of 7075 alloy was observed and the strengthening mechanism was analyzed

(1) A vertical rheo squeeze casting machine with translational gating system was developed to realize the squeeze casting of “translational gating and pressure solidification”. The filling process can avoid the gas entrapment of alloy melt and realize the secondary cavity extrusion (forging) function in squeeze casting.

(2) The forming and heat treatment process of 7075 alloy by rheo squeeze casting with translational pouring and pressure solidification was established. The average tensile strength, yield strength and elongation of the product were 520mpa, 467mpa and 9.05%, respectively.

(3) The tensile fracture mechanism of 7075 alloy formed by rheo squeeze casting after heat treatment was revealed. The equivalent stress model of void under tensile stress was established. It was confirmed that the primary melt void was the main reason for the decrease of elongation.