热处理对HA/Mg-Zn-Ca生物复合材料显微组织及性能的影响

采用剪切搅拌铸造结合热挤压工艺制备了1HA/Mg-3Zn-0.2Ca(质量分数,%)复合材料,研究了固溶及时效处理对挤压态1HA/Mg-3Zn-0.2Ca复合材料显微组织、力学性能及电化学腐蚀行为的影响。结果表明:挤压态复合材料经固溶处理(T4)后,第二相数量减少,晶粒尺寸增大,屈服强度降低,但延伸率和耐蚀性能有所提高。固溶超过3 h后,由于晶粒尺寸过分长大耐蚀能力又出现下降;固溶后时效处理(T6),复合材料屈服强度提高,耐蚀性变化不大。因此,对挤压态HA/Mg-Zn-Ca复合材料进行适当的固溶及时效处理可以提高复合材料的耐蚀性及延伸率。

Effects of heat treatment on microstructures and properties of HA/Mg-Zn-Ca biocomposite

Magnesium and magnesium alloys have attracted increasing attention as implant materials due to their suitable mechanical properties with bones, good biocompatibility and biodegradability in physiological environment. The addition of bioceramic particles into magnesium alloy can adjust mechanical properties as well as the corrosion properties to meet the requirements service performance. In this paper, 1HA/Mg-3Zn-0.2Ca composities were fabricated by means of melt high shearing technology combined with following hot extrusion. Effects of heat treatment on microstructures, mechanical and corrosion resistance properties were investigated. The results indicated that after solid solution treatment (T4 treatment), the amounts of secondary phases in 1HA/Mg-3Zn-0.2Ca composite decreases, grain size became larger, yield strength decreased, the elongation and the corrosion resistance increased. However, the corrosion resistance show a decreasing trend as the solid solution treatment time exceeded 3h , which was attributed to grain size is overlarge. Aging treatment after solid solution, the yield strength increased and the corrosion resistance was not changed obviously. Hence, the as-extruded 1HA/Mg-3Zn-0.2Ca composite can be improved the corrosion resistance and elongation by suitable solid solution and aging heat treatment.