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

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 pri-mary and eutectic Mg2Si phase can be greatly modified by the yttrium (Y) addition. The size of the primary Mg2Si phases can be reduced to similar to 20 mu m 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.