Effect of minor content of Gd on the mechanical and degradable properties of as-cast Mg-2Zn-xGd-0.5Zr alloys

By Chen, Junxiu; Tan, Lili; Yu, Xiaoming; Yang, Ke
Published in Journal of Materials Science & Technology 2019

Abstract

RE-containinabstextg Mg alloys used as biodegradable medical implants exhibit good promising application due to their good mechanical properties and degradation resistance. In this work, effect of Gd on the microstructure, mechanical properties and biodegradation of as-cast Mg-2Zn-xGd-0.5 Zr alloys was investigated. The results showed that there were mainly ?-Mg, I-phase, W-phase and MgZn2 phase in Mg-Zn-Gd-Zr alloys. With increase of the Gd content, the strength of the alloys was enhanced due to the second phase strengthening and grain refinement. The degradation resistance of Mg-2Zn-0.5 Zr alloy was increased by adding 0.5-1% Gd due to the uniformly distributed second phases which acted as a barrier to prevent the pitting corrosion. However, increasing Gd content to 2% reduced the degradation resistance of the alloy due to the galvanic corrosion between the matrix and the second phases. The good degradation resistance and mechanical properties of as-cast Mg-2Zn-1Gd-0.5 Zr alloy makes it outstanding for biomaterial application.

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