Effect of deformation temperature and strain rate on semi-solid deformation behavior of spray-formed Al-70%Si alloys
(1. State Key Laboratory for Advanced Metals and Materials,
University of Science and Technology Beijing, Beijing 100081, China;
2. General Research Institute for Nonferrous Metals, Beijing 100088, China)
University of Science and Technology Beijing, Beijing 100081, China;
2. General Research Institute for Nonferrous Metals, Beijing 100088, China)
Abstract: Spray-formed Al-70%Si(mass fraction) alloys were deformed by compression in the semi-solid state. The effects of the deformation temperature, strain rate and the microstructure were studied. Two strain rates(1s-1 and 0.1s-1) and six deformation temperatures (600℃, 720℃ , 780℃, 900℃, 1000℃ and 1100℃) were chosen. The stress—strain curve exhibits a peak at low strain and then decreases to a plateau before it starts to increase again as the strain increases. The stress required for deformation at lower strain rate and at higher deformation temperatures is less than those at higher strain rate and at lower deformation temperatures. Four mechanisms of semi-solid deformation can be used to explain the different behaviors of the stress—strain curves under different conditions.
Key words: Al-70%Si alloy; semi-solid state; stress—strain curve