An Investigation on the Effects of Pre-deformation and Temperature on Thixotropic Microstructure of AA2014 Aluminum Alloy

摘要

With copper as the main alloying addition, alloy from the 2XXX family offers high strength at low specific weight and are widely employed for aircraft, wheels and major structural components. However, they suffer from low forming speeds and require high forming pressures. Hence, it is very attractive to form these alloys in semisolid state for technical and economical reasons. In this study, one of the most important wrought alloys for aerospace applications, AA2014 was used. In order to form the best semi-solid forming products, thixotropic character must be known. For this purpose, AA2014 alloy as-cast and warm extruded samples were heated to 600, 610 and 620 A degrees C in semi-solid region and held for 0, 5 and 10 min in the induction coil. All samples were cooled with water at room temperature. Microstructure analysis was conducted with metallographic methods and shape factor values were calculated. With increasing predeformation rate and heating temperature, the shape factor increases. Experimental results show that spherical shaped thixotropic microstructures which is required for semi-solid forming can be created in AA2014 alloy.