Grain Refinement of Zn-50Al Alloy through the Addition of Zn-Al-Ti-C Master Alloy

Abstract:

In this paper, two types of Zn-Al-Ti-C master alloy with different Ti/C ratios were produced throug a two-step method, characterized by XRD and SEM, and their refinement behaviors and mechanism in Zn-50Al alloy were studied. Both of the master alloys remarkably reduced the size of α-Al grains, impeded the dendritic growth and promote the equiaxed growth of α-Al grains in Zn-50wt.%Al alloy. The master alloy containing both TiC and dditional Ti in the Zn-Al matrix was found to have higher refinement ability than that containg only TiC. The refinement effect of both master alloys was greatly enhanced as the solidification temperature of Zn-50Al melt decreases. TiC particles were observed to be located at the center of α-Al grains and act as the nucleating substrate for α-Al. The decrease of melt solidification temperature and the presence of additional Ti atoms in the Zn-50Al melt cause higher melt supercooling, which further elevate the nucleating rate of α-Al grains on TiC particles and promote the equiaxed growth of α-Al grains.

• Periodical: Advanced Materials Research (Volumes 452-453)
• Pages: 339-343
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.452-453.339
• Online since: January 2012
• Authors: Z.Q. Wang, W.J. Li, Z.X. Yang, H.R. Geng, W.H. Wang, S.L. Chen, W.T. Zhao
• Keywords: Grain Refinement, TiC Particle, Zn-Al Alloy, Zn-Al-Ti-C Master Alloy

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