Effect of hot extrusion on microstructure and tribological behavior of Al_(2)O_(3p) reinforced 7075 aluminum-matrix composites  

热挤压对Al_(2)O_(3p)增强7075铝基复合材料微观组织和摩擦学行为的影响

作　　者：LEI Yu-shun YAN Hong WEI Zhi-fan XIONG Jun-jie ZHANG Peng-xiang WAN Jian-ping WANG Zhi-lu 雷雨顺;闫洪;魏志帆;熊俊杰;张鹏翔;万剑平;王志录(School of Mechanical and Electrical Engineering,Nanchang University,Nanchang 330031,China;Key Laboratory of Light Alloy Preparation and Processing in Nanchang City,Nanchang 330031,China;Jinghang Aviation Forging and Casting Co.,Ltd.,Jingdezhen 333000,China)

机构地区：[1]School of Mechanical and Electrical Engineering,Nanchang University,Nanchang 330031,China [2]Key Laboratory of Light Alloy Preparation and Processing in Nanchang City,Nanchang 330031,China [3]Jinghang Aviation Forging and Casting Co.,Ltd.,Jingdezhen 333000,China

出　　处：《Journal of Central South University》2021年第8期2269-2284,共16页中南大学学报（英文版）

基　　金：Project(51965040)supported by the National Natural Science Foundation of China;Project(20181BAB206026)supported by the National Science Foundation of Jiangxi Province,China。

摘　　要：The effects of hot extrusion and addition of Al_(2)O_(3p) on both microstructure and tribological behavior of 7075 composites were investigated via optical microscopy(OM),scanning electron microscopy(SEM),energy dispersive spectrometry(EDS),and transmission electron microscopy(TEM).The experimental consequences reveal that the optimal addition of Al_(2)O_(3p) was 2 wt%.After hot extrusion,the Mg(Zn,Cu,Al)2 phases partially dissolve into the matrix and generate many uniformly distributed aging precipitation particles,the Al_(7)Cu_(2)Fe phases are squeezed and broken,and the Al_(2)O_(3p) become uniform distribution.The microhardness of as-extruded 2 wt%Al_(2)O_(3p)/7075 composites reaches HV 170.34,increased by 41.5%than as-cast composites.The wear rate of as-extruded 2 wt%Al_(2)O_(3p)/7075 composites is further lower than that of as-cast composites under the same condition.SEM-EDS analyses reveal that the reinforced wear resistance of composites can put down to the protective effect of the Al_(2)O_(3p) reinforced transition layer.After hot extrusion,the transition layer becomes stable,which determines the reinforced wear resistance of the as-extruded composites.通过光学显微镜(OM)、扫描电子显微镜(SEM)、能谱仪(EDS)和透射电子显微镜(TEM)研究了热挤压和Al_(2)O_(3p)的添加对7075复合材料的微观结构和摩擦学行为的影响。实验结果表明,Al_(2)O_(3p)的最佳添加量为2%(质量分数)。经热挤压后,Mg(Zn,Cu,Al)2相部分溶解到基体中,并且产生了许多均匀分布的时效析出颗粒,Al_(7)Cu_(2)Fe相被挤压并破碎,Al_(2)O_(3p)分布变得均匀。2%质量分数的Al_(2)O_(3p)/7075复合材料的显微硬度达到HV 170.34,相比铸态复合材料提高了41.5%。在相同条件下,挤压态2%质量分数的Al_(2)O_(3p)/7075复合材料的磨损率比铸态复合材料的磨损率更低。SEM-EDS分析表明,复合材料耐磨性的增强主要取决于Al_(2)O_(3p)增强的过渡层的保护作用。经过热挤压后,摩擦过渡层变得稳定,这使得挤压态复合材料的耐磨性增强。

关 键 词：7075 alloy AL2O3P COMPOSITES hot extrusion MICROSTRUCTURE tribological behavior 

分 类 号：TB333[一般工业技术—材料科学与工程]