Study on Reheating Process of AIMg0.9Si0.6 Alloy by Semi-Continuous Casting of Low Superheat

Microstructures and grain size of AlMg0.9Si0.6 alloy billet prepared by semi-continuous casting of low superheat,and reheated at different heating temperature and with different holding time,were observed by optical microscope.The image analyzing software combining with differential scanning calorimetry(DSC)was used to investigate the microstructure evolution and grain growth during reheating process.The results show that the microstructural evolution is affected by reheating temperature and holding time.With increasing in heating temperature and extending in holding time,the grain grows spherically and gradually.The microstructural evolution is faster and faster with increasing in heating temperature,and the grain grows more and more spherically with extending in holding time.The AlMg0.9Si0.6 alloy billets with homogeneous,round and fine grains can be prepared by effectively controlling reheating temperature and holding time.