Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7221223 | Materials & Design (1980-2015) | 2013 | 7 Pages |
Abstract
Overlapping of laser beam tracks has significant influence on surface quality of laser-treated materials. This paper examines how overlapping tracks affect heat flow, solidification microstructure and electrochemical behavior of laser-melt magnesium alloy. Microstructure evolution of laser-melt surface with different overlapping rates at optimized scanning speed is investigated. Results show that solidification microstructure changes from cellular grains to cellular-dendritic and equiaxed dendritic in the overlapped area when overlapping rate increases. Numerical model suggests that Marangoni convection plays a predominate role in determining the solidification microstructure, and it increases significantly with the overlapping rate. The effect of microstructure in-homogeneities caused by overlapping on electrochemical behavior has also been analyzed.
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Authors
Y.C. Guan, W. Zhou, Z.L. Li, H.Y. Zheng,