Enhancing mechanical properties and degradation performance of Mg−0.8wt.%Ca alloy by directional solidification

• Published in: Transactions of Nonferrous Metals Society of China Vol. 33; no. 2; pp. 409 - 421
• Main Authors: ZHANG, Yi, FENG, Xiao-hui, HUANG, Qiu-yan, LI, Ying-ju, YANG, Yuan-sheng
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.02.2023
• Subjects: degradation performance; directional solidification; mechanical properties; Mg−Ca alloy; microstructure; microstructure; degradation performance; Mg−Ca alloy; directional solidification; mechanical properties
• ISSN: 1003-6326
• DOI: 10.1016/S1003-6326(22)66116-8

The mechanical properties and degradation performance in Hank's solution of the directionally solidified (DSed) Mg−0.8Ca (wt.%) alloys were investigated and compared with those of the as-cast alloy. The microstructure was studied by OM, SEM, TEM, and EBSD. It is found that the columnar grains in DSed alloys have a consistent growth orientation of . The mechanical strength and ductility of Mg−0.8Ca alloy are significantly improved after directional solidification. Besides, the corrosion resistance of Mg−0.8Ca alloy in Hank's solution is dramatically enhanced after directional solidification. The Mg−0.8Ca alloys in Hank's solution mainly undergo microgalvanic corrosion, and the corrosion products consist of Mg(OH)2, (Ca, Mg)3(PO4)2, and hydroxyapatite (HA). The superior properties of the DSed Mg−Ca alloy are beneficial from the columnar microstructure and the redistribution of the eutectics. The DSed Mg−0.8Ca alloy with columnar dendritic structure is expected to be used as biodegradable materials.