Characterization and Properties of Mg-xGd-1.5Nd-0.5Zn-0.5Zr Alloys for Biodegradation Applications

Materials

Zhixin Kang¹  Junyi Zhang²  Zhenzhen Gui³ 

[1] Automotive Engineering, South China University of Technology, 381 Wushan Road, Guangzhou 510640, China;;Guangdong Key Laboratory for Advanced Metallic Materials Processing, School of Mechanical &School of Mechanical and Electrical Engineering, Guangzhou University, 230 Wai Huan Xi Road, Guangzhou Higher Education Mega Center, Guangzhou 510006, China;

关键词: magnesium alloys;    microstructure;    mechanical properties;    corrosion resistance;   

DOI  :  10.3390/ma13061421

来源: DOAJ

【 摘 要 】

The differences in microstructural characteristics, mechanical properties, and corrosion behavior of the as-cast and solution-treated Mg-xGd-1.5Nd-0.5Zn-0.5Zr alloys (Mg-xGd, x = 1, 3, and 5) were studied and discussed. The as-cast Mg-xGd alloys mainly consisted of an α-Mg and island-like eutectic (Mg,Zn)₃RE phase, a few cuboidal phases (REH₂), and a ZnZr phase. With the increase of Gd content, the grain sizes of the as-cast Mg-xGd alloys decreased. Compared to the microstructure of the as-cast Mg-xGd alloys, the eutectic (Mg,Zn)₃RE phase disappeared and the cuboidal REH₂ phases existed in the solution-treated Mg-xGd alloys. A large amount of ZnZr_x phase was precipitated from α-Mg in the Mg-3Gd alloy and demonstrates a flower-like distribution. The ultimate tensile strength (UTS) and yield strength (YS) of the solution-treated Mg-xGd alloys increased with an increasing Gd content, with the UTS and YS of the Mg-5Gd alloys reaching 217.5 and 125.2 MPa, respectively. Immersion and electrochemical tests showed that the as-cast Mg-3Gd alloy presented the best corrosion resistance with a corrosion rate of 0.285 mm/yr. The corrosion resistance of the solution-treated Mg-3Gd alloy attained the lowest value (0.973 mm/yr), due to the large quantities of ZnZr_x with a flower-like phase distribution, forming series of galvanic couple groups with the α-Mg.

【 授权许可】

Unknown