Microstructural characteristics of thixoforged A356 alloy in mushy state

来源期刊：中国有色金属学报(英文版)2010年第z3期

论文作者：S. TAHAMTAN A. FADAVI BOOSTANI

文章页码：781 - 787

Key words：thixoforging; rheocasting; tensile properties; hot working; fracture surface

Abstract: Tensile properties of a thixoforged A356 alloy were measured and compared with those of rheocast and gravity cast alloys with the same composition. In the thixoforging process, A356 rheocast alloy produced by stirring method was reheated to 600 ℃ or 610 ℃, held for 10 min, and then 50% deformation was applied. Microstructure, tensile properties and fracture surfaces of produced specimens were then investigated. Results obtained show that tensile strength, yield strength and elongation-to-failure of thixoforged samples formed at lower temperature are higher than those of samples formed at higher temperature. By increasing temperature, in the case of thixoforged samples, tensile fracture path is changed from trans-primary alpha phase to inter-primary alpha phase. Differences observed in the tensile fracture path and improvement in the mechanical properties due to thixoforging process is attributed to microstructural changes as well as morphological aspects of silicon phase.