搅拌摩擦加工对7075铝合金微观组织和力学性能的影响  

Effect of Friction Stir Processing on Microstructure and Mechanical Properties of 7075 Aluminum Alloy

作　　者：潘胜善 杨炳元 袁晓红 龙绍檑 桂琴 陈延益 蔡杰 杨艳菲 赵慧芳 PAN Shengshan;YANG Bingyuan;YUAN Xiaohong;LONG Shaolei;GUI Qin;CHEN Yanyi;CAI Jie;YANG Yanfei;ZHAO Huifang(Guizhou Normal University,Guiyang 550025,China;Guizhou Institute of Technology,Guiyang 550003,China;Guizhou Yonghong Heat Exchanger and Cooling Technology Co.,Ltd.,Qiannan 550600,Guizhou,China)

机构地区：[1]贵州师范大学,贵阳550025 [2]贵州理工学院,贵阳550003 [3]贵州永红换热冷却技术有限公司,贵州黔南州550600

出　　处：《焊管》2024年第12期44-51,共8页Welded Pipe and Tube

基　　金：贵州省基础研究计划(自然科学类)项目“共晶型难熔高熵合金涂层激光-感应复合熔覆增材制造及其高温摩擦行为研究”(项目编号黔科合基础-ZK[2024]一般516);贵州省基础研究计划(自然科学类)项目“有效变形体积与高强钢多层次组织的复合关系及对塑韧性的控制研究”(项目编号黔科合基础[2020]1Y199)。

摘　　要：为了提高7075铝合金的表面强度、制备高强度超细晶铝合金材料,利用搅拌摩擦加工(FSP)对7075铝合金进行表面处理,优化其微观结构,通过扫描电子显微镜(SEM)、电子背散射衍射(EBSD)等对微观组织进行定量表征,采用万能试验机对其力学性能进行测试,揭示其对微观组织和力学性能的影响机制。研究表明,经FSP后材料的晶粒由板条状形态转变为细小均匀等轴晶,尤其是试样因充分的再结晶(再结晶晶粒比例高达95%)导致晶粒尺寸最小达到0.66μm;FSP后7075铝合金的抗拉强度呈先增后降的趋势,最大值达到537 MPa;FSP后的铝合金塑性明显高于母材,试样通过超细晶产生晶界滑移来协调塑性变形,使其塑性最优,相比母材试样增加了83.3%。研究结果可为制备高强度的超细晶材料提供技术参考。In order to improve the surface strength of 7075 aluminum alloy and make high⁃strength ultra⁃fine crystal aluminum alloy material,the microstructure of 7075 aluminum alloy was optimized by friction stir processing(FSP).The microstructure was quantitatively characterized by scanning electron microscopy(SEM)and electron backscatter diffraction(EBSD),and the influence mechanism of microstructure on mechanical properties was revealed.Results show that after FSP,grain size of material changes from strip shape to fine and uniform equiaural crystal,especially for sample due to sufficient recrystallization(95%of the recrystallization grains),grain size is the smallest,reaching 0.66μm.Tensile strength of 7075 aluminum alloy after FSP increased first and then decreased,and reached the maximum value(537 MPa)in processed sample.Plasticity of aluminum alloy after FSP is significantly higher than that of base material,and processing sample produces grain boundary slip to coordinate plastic deformation through ultra⁃fine crystals,resulting in optimal plasticity,which increases by 83.3%compared with sample.Research results can provide technical reference for the preparation of high strength ultrafine materials.

关 键 词：7075铝合金 搅拌摩擦加工 微观结构 力学性能 再结晶 

分 类 号：TG456.9[金属学及工艺—焊接]