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为改善复合材料中纳米增强体易团聚的问题,将陶瓷纳米棒HA进行表面包覆Mg O改性处理(m-HA),并采用高熔体剪切搅拌技术制备Mg-3Zn-0.8Zr合金(MZZ)、Mg-3Zn-0.8Zr/1HA复合材料(MZZH)和Mg-3Zn-0.8Zr/1m-HA复合材料(MZZMH)。研究了m-HA对Mg-Zn-Zr/HA复合材料微观组织、力学性能和耐蚀性能的影响。结果表明,陶瓷纳米棒HA的加入细化了MZZ合金的组织,提高了MZZ合金的力学性能和电化学耐蚀性能。与MZZH相比,MZZMH的晶粒更加细小均匀,陶瓷纳米棒在基体中的分布更均匀。挤压态MZZMH的力学性能较MZZH显著提高,其硬度、屈服强度、抗拉强度和延伸率分别达到92 HV、291 MPa、325 MPa和8.62%。MZZMH的自腐蚀电位比MZZH高59 m V,MZZMH的腐蚀速率较MZZH降低,在SBF中浸泡7 d后稳定在5 mm/a。腐蚀机理的不同使MZZMH复合材料的耐蚀性能优于MZZH。因此,MgO改性可有效促进HA纳米棒的均匀分布,进而显著提高MZZMH的力学性能和耐蚀性。
In order to improve the easy-agglomeration of nano-reinforcements in composites, the surface of Mg-3Zn-0.8Zr alloy (m-HA) (MZZ), Mg-3Zn-0.8Zr / 1HA composites (MZZH) and Mg-3Zn-0.8Zr / 1m-HA composites (MZZMH). The effects of m-HA on the microstructure, mechanical properties and corrosion resistance of Mg-Zn-Zr / HA composites were studied. The results show that the addition of ceramic nanorods HA refine the microstructure of MZZ alloy and improve the mechanical properties and electrochemical corrosion resistance of MZZ alloy. Compared with MZZH, MZZMH grains are more fine and uniform, and the distribution of ceramic nanorods in the matrix is more uniform. The mechanical properties of extruded MZZMH were significantly higher than that of MZZH, and its hardness, yield strength, tensile strength and elongation reached 92 HV, 291 MPa, 325 MPa and 8.62% respectively. The self-corrosion potential of MZZMH is 59 mV higher than that of MZZH. The corrosion rate of MZZMH is lower than that of MZZH, and it is stable at 5 mm / a after soaking in SBF for 7 days. The corrosion mechanism makes MZZMH composite corrosion resistance better than MZZH. Therefore, MgO modification can effectively promote the uniform distribution of HA nanorods, and then significantly improve the mechanical properties and corrosion resistance of MZZMH.