MgO改性HA对Mg-Zn-Zr/m-HA复合材料组织及性能的影响  

Effects of MgO Modified HA Nanoparticles on the Microstructure and Properties of Mg-Zn-Zr/m-HA Composites

作　　者：郑浩然 陈民芳[1,2] 李祯 由臣[1] 刘德宝[1] 

机构地区：[1]天津理工大学材料科学与工程学院,天津300384 [2]天津理工大学天津市光电显示材料与器件重点实验室,天津300384

出　　处：《金属学报》2017年第10期1364-1376,共13页Acta Metallurgica Sinica

基　　金：国家自然科学基金项目No.51371126;天津市科技重大专项与工程计划No.15ZXQXSY00080;天津市高等学校科技发展基金项目No.20110301~~

摘　　要：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。Magnesium metal matrix composites（MMCs） are hot research spots in recent years because of their adjustable mechanical and corrosion properties. However, the agglomerate particles in MMCs limit its applications in many areas. In order to solve this problem, Mg O surface modified hydroxyapatite ceramic nanorods（m-HA） were prepared and added as reinforcement in this work. Mg-3Zn-0.8Zr alloy（MZZ）, Mg-3Zn-0.8Zr composites with unmodified（MZZH） and modified（MZZMH） nanorods were produced by high shear mixing technology. Effects of m-HA nanorods on the microstructure, mechanical properties and corrosion properties of Mg-Zn-Zr/m-HA composites were investigated. The results showedthat the addition of HA nanorods refined the grain size of MZZ alloy and gave a raise to the mechanical properties and electrochemical corrosion resistance of MZZ alloy. The grain size of MZZMH was smaller than that of MZZH and the distribution of m-HA nanorods in the matrix was more uniform than that of HA nanorods. Moreover, the as-extruded MZZMH composite exhibited a yield tensile strength of 291 MPa and ultimate tensile strength of 325 MPa, greater than that of MZZH. The corrosion potential of MZZMH was approximately 59 m V greater than that of MZZH. The corrosion rate of MZZMH was 5 mm/a after immersion 7 d in SBF, lower than that of MZZH. The corrosion resistance of MZZMH was better than that of MZZH due to the different corrosion mechanism. Surface corrosion products of MZZMH was alternating Mg（OH）_2 and Ca-P compound at the early stage of immersion, but surface corrosion layer of MZZH specimen was always Mg（OH）_2. The mechanical properties and corrosion resistance of Mg-Zn-Zr/m-HA composites were improved by the addition of m-HA.

关 键 词：MgO包覆HA纳米棒 镁基复合材料 微观组织 力学性能 腐蚀性能 

分 类 号：TB333[一般工业技术—材料科学与工程]