Microstructural properties and mechanical behavior of magnesium/hydroxyapatite biocomposite under static and high cycle fatigue loading

作者：Sabet A S; Jabbari A H; Sedighi M^*

来源：Journal of Composite Materials, 2018, 52(13): 1711-1722.

DOI：10.1177/0021998317731822

• Magnesium
• hydroxyapatite biocomposite
• fatigue life
• microstructure
• mechanical behavior
• stir-casting

In this study, magnesium/hydroxyapatite biocomposites having 2.5 and 5wt% of hydroxyapatite have been fabricated using stir casting followed by hot extrusion method. Both microstructural and mechanical behaviors of these composites have been studied, which contain particle distribution, grain size, microhardness, tension, and compression tests. Then, high cycle fatigue tests were performed using a rotating-bending testing machine (under stress ratio of R=-1). The results indicate an acceptable particle distribution and grain refinement in the composites. Also, the microhardness of the composites has been increased in comparison with the pure extruded sample. The yield stress has been enhanced in both tension and compression tests by increasing the amount of reinforcement, while the maximum strain reduced. Moreover, the fabricated biocomposites revealed better overall high cycle fatigue life in comparison to pure Mg, and infinite life (>10(7) cycles) could be achieved in the composites. Scanning electron microscope images of the fracture surfaces showed that the agglomeration of hydroxyapatite particles is one of the most important criteria for crack initiation in the composites.

• 出版日期2018-6