6061铝合金搅拌摩擦焊接工艺研究.pdf

西南交通大学硕士研究生学位论文第1页摘要本文对6061铝合金进行了搅拌摩擦焊接(FSW)I艺试验,研究了焊接接头的力学性能和微观组织。力学性能试验的结果表明,6061铝合金搅拌摩擦焊接接头的强度可达母材的79%;由金相试验结果可知搅拌摩擦焊接接头主要分为五个区,焊核区、前进侧以及后退侧热机影响区、前进侧以及后退侧热影响区,每个区域由于经历的机械搅拌和焊接热循环作用不同,在微观组织和力学性能上有很大的不同。为了研究各个区域微观组织及力学性能不同的原因,采用热电偶测温的方法测量除了焊核区之外的各个区域的温度,并通过ANSYS热分析得到焊核区的温度。结果表明热影响区的热循环最高温度约为300。C,热机影响区热循环的最高温度达到350。C, 焊核区的热循环的最高温度达到450℃。通过人工神经网络建立了6061铝合金FSW的焊接质量专家系统,利用此系统对工艺参数进行优化,得到焊接参数为1 100rpm、焊接速度180mm/min、 时接头具有最高的强度,而此参数的实测数据为188MPa。关键词:搅拌摩擦焊;6061铝合金;力学性能;微观组织;工艺参数优化西南交通大学硕士研究生学位论文第1I页皇曼曼曼曼曼曼曼蔓曼曼舅舅量曼璺I|.I I———— I曼曼曼曼曼曼曼曼曼曼舅 Ab stract Inthispaper,the process ofstirwelding frictionof 6061 aluminum alloy was studied· The mechanical properties and microstructure ofthe welded joint resultsshow that,thejoint hasgood mechanical properties,reaches 79%strength ofthebase metal and good microstructure observmion indicates thatthe friction stir welding ioint isdivided intofiveregions:the weld nugget zone,theromal—mechanical affectedzone,and the base microstructure and mechanical properties of each region isvery different form each other,just beacause they have experienced different mechanical and thermalcycle effects. The thermal cycle of theFsW joint except thenugget zone,was measured by therlTlocouplesystem,Furthermore,temperature ofthenugget zone was evaluated by ANSYS thermal results show thatthehighesttemperature ofthermal cycle of affected zone isabout 350 oC,the heataffected zone isabout 300 oC, andthenugget zone isabout 450oC. The prediction system of606 friction stirwelding was established by system can predict the tensile property accurately,and optimize thewelding results show withtheparameters of 00rad/min, 80mm/min andpressed hasthehighest Strength. Keywords:FSW;6061 aluminum alloy;mechanical properties;microstructure;optimization ofwelding parameters 西南交通大学硕士研究生学位论文第1页曼曼曼曼曼曼曼曼曼皇量曼曼曼曼曼曼曼曼曼皇曼曼曼!鼍lii曼曼曼