Semisolid microstructural evolution of fine grain in situ Mg2Sip/AM60B composite in mushy zone

• DOI: 10.1179/1432891715z.0000000002085
• Publication Date: 2015-12-14T14:21:01Z
• Authors: S. Q. Zhang; T. J. Chen; P. B. Li; L. L. Li
• Keywords: 02 engineering and technology; 0210 nano-technology

AbstractThe semisolid microstructural evolution of refined in situ Mg2Sip/AM60B composite in the mushy zone has been investigated. The results indicated that the adopted refining technique is effective for the composite. The non-dendritic microstructure with fine and spheroidal solid particles could be obtained after being partially remelted at the mushy zone for 30 minutes. Reheating temperature affects the size, shape factor and composition of the primary α-Mg particles and liquid fraction of the semisolid system. These effects result from phase transformation rate, which is determined by the atom diffusion ability. Rising the reheating temperature is beneficial for achieving small and spheroidal particles, but increases in the amount of liquid phase. The most appropriate reheating temperature range of the current composite is 600–605°C. The lower reheating temperature results in coarsening of primary α-Mg particles.