Tensile Properties and Wear Resistance of Mg Alloy Containing High Si as Implant Materials

Abstract

Magnesium alloy has been considered as one of the third-generation biomaterials for the regeneration and support of functional bone tissue. As a regeneration implant material with great potential applications, in-situ Mg2Si phase reinforced Mg-6Zn cast alloy was comprehensively studied and expected to possess excellent mechanical properties via the refining and modifying of Mg2Si reinforcements. The present study demonstrates that the primary and eutectic Mg2Si phase can be greatly modified by the yttrium (Y) addition. The size of the primary Mg2Si phases can be reduced to ~20 μm with an addition of 0.5 wt.% Y. This phenomenon is mainly attributed to the poisoning effect of the Y element. Moreover, wear resistance and tensile properties of the ternary alloy have also been improved by the Y addition. Mg-6Zn-4Si-0.5Y alloy exhibits optimal tensile properties and wears resistance. The ultimate tensile strength and the elongation of the alloy with 0.5 wt.% Y are 50% and 65% higher than those of the ternary alloy, respectively. Excessive Y addition (1.0 wt.%) deteriorates the tensile properties of Mg-Zn-Si alloy. The improvement of the tensile properties is mainly due to the modification of primary and eutectic Mg2Si phases as well as the solid solution strengthening of the Y atoms. This study provides a certain implication for the application of Mg-Zn-Si alloys containing Y elements as regeneration implants.