Intermetallics 2018-02-03

Application of laser remelting process on the Zr-Cu based alloy composite

Huei-Sen Wang, Hou-Guang Chen, Yi-Ting Liu, Jason Shian-Ching Jang

Index: 10.1016/j.intermet.2018.01.012

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Abstract

In this study, a 1.0 mm thick (Zr48Cu32Al8Ag8,Ta4)Si0.75 alloy composite (AC) plate was laser remelted (LR) by employing the Nd:YAG laser technique. To fully remelt the plate, a two-sided welding process with preselected parameters was employed. The microstructure, mechanical (microhardness), thermal properties, and corrosion resistance (potentiodynamic polarization) of the laser remelted alloy composite (LR-AC), the Zr-Cu AC (with the crystalline structure), and the Zr-Cu based bulk metallic glass composite (BMGC, the same composition as the AC. The amorphous matrix is produced by a rapid cooling rate) were then investigated and compared. The test results show that after the laser remelting processes, the LR-AC consisted of an amorphous matrix and reinforced phase, Ta, in the remelted areas, which is similar to the BMGC; however, the volume fractions and grain size of the micro-sized reinforced phase, Ta, in the LR-AC were reduced. When compared to those of the BMGC, the GFA indices of LR-AC were slightly improved. For the hardness tests, LR-AC showed a similar hardness to that of the BMGC; however, a higher value was obtained when compared to that of the AC. Furthermore, the LR-AC exhibits a lower Icorr (a slower corrosion rate), which is attributed to the amorphous matrix and less micro-sized Ta content, eliminating corrosion occurring between the Ta and the matrix of the alloy.