Microstructure formation mechanism and properties of a Mg-3Sn-1Mn (wt%) magnesium alloy processed by a novel semisolid continuous shearing and rolling process

Abstract

A novel semisolid Continuous Shearing and Rolling (CSR) process for producing a Mg-3Sn-1Mn (wt%) alloy strip is developed, and the microstructure formation mechanism and properties of the Mg-3Sn-1Mn (wt%) alloy processed by this process are investigated. At a casting temperature of 690A degrees C and a roll speed of 0.052 m center dot s(-1), a Mg-3Sn-1Mn (wt%) alloy strip with a cross section size of 4x160 mm was produced by the proposed process. Under strong cooling and shearing actions, eruptive nucleation, direct globular grain growth and dendrite arm breakage took place during the process, which caused formations of fine spherical grains. The grain size and roundness of the Mg-3Sn-1Mn (wt%) alloy strip increased with increasing increments of the casting temperature. In this perspective, roll speed obviously affects grain shape. The ultimate tensile strength and elongation of the Mg-3Sn-1Mn (wt%) alloy strip reached 205.93 MPa and 7.2%.