Effect of minor Ni addition on the microstructure, mechanical properties and corrosion behavior of Mg–2Gd alloy

• Published in: Journal of materials research and technology 2022-09, Vol.20, p.3735-3749
• Main Authors: Wang, Yongqin, Zhang, Dingfei, Zhong, Shiyu, Dai, Qimin, Hua, Jianrong, Luo, Yulun, Hu, Guangshan, Xu, Junyao, Jiang, Bin, Pan, Fusheng
• Format: Article
• Language: English
• Subjects: Corrosion behaviors; Mechanical properties; Mg-Gd alloy; Ni addition
• ISSN: 2238-7854
• DOI: 10.1016/j.jmrt.2022.08.051

The demand for soluble magnesium alloys with high plasticity used for sealing tools in petroleum field is increasing. Here, the effects of Ni content (0.1, 0.2 and 0.5wt.%) on microstructure, mechanical properties and corrosion rate of Mg-2Gd alloy were studied. The volume fraction of LPSO phases and the average grain size (α-Mg) increased and decreased with the increase of Ni content, respectively. After adding Ni, the texture changed from the rare earth texture to the basal fiber texture, and the strength, hardness and corrosion rate were increased with an acceptable decrease in elongation: the ultimate tensile strength/elongation/corrosion rate of the Mg-2Gd alloy and Mg-2Gd-0.5Ni alloy were 191 MPa/23.1%/15.2 mm·y-1, 287 MPa/18.1%/499.9 mm·y-1, respectively. Therefore, the addition of Ni effectively improved the strength and degradation rate of the Mg-2Gd alloy, which was mainly due to the grain refinement, the enhancement of basal fiber texture and the appearance of LPSO phases.