Process Parameter Optimizing and Studies on Microstructure and Properties of AZ31 Alloy Prepared by Semisolid Rolling Process

A novel continuous semisolid rolling process for producing AZ31 alloy strip was developed. The process parameters were optimized, and microstructure and properties of AZ31 alloy prepared by the process were studied. The results reveal that primary grains of the strip become coarse, and the grain structure transforms from round shape to dendrite with the increment of casting temperature gradually. Eutectic phase fraction and primary grain size increase with the increment of roll speed. The primary grain size decreases firstly and then increases with the increment of the vibration frequency correspondingly. When the casting temperature is from 650 degrees C to 690 degrees C, the roll speed is 0.069 m.s(-1), and the vibration frequency is about 80 Hz, AZ31 alloy strip with a cross section size of 4 mm x 160 mm was prepared by the proposed process. The ultimate tensile strength and elongation are improved 1% and 57%, respectively.