2Al2铝合金点焊微裂纹高温愈合行为的研究
|
摘要
选用2Al2高强铝合金,采用三相次级整流电阻点焊机和特定的焊接参数预制内裂纹,然后在2Al2铝合金固溶温度(500℃)下对接头内裂纹进行6 h的高温愈合处理。采用金相显微镜、扫描电镜和室温力学性能测试等手段分析接头的微观组织形貌、裂纹形态及断口形貌,研究接头中裂纹的高温愈合行为及愈合行为对接头力学性能的影响。结果表明,在高温热量作用下,接头微观组织整体均匀化,裂纹产生局部愈合,接头塑性有所改善,接头断裂方式由解理断裂转变为准解理断裂。但经过高温愈合处理后,接头显微硬度和剪切性能均有所下降。
In this article, it adopted three-phase secondary rectification resistance spot welding machine and specific welding parameters to prefabricate inner cracks in 2Al2 high-strength aluminum alloy, then the inner cracks in welded joints of 2Al2 were carried out high temperature healing treatment at solution temperature(500 ℃) for 6 hours. The microstructure, crack morphology,and fracture morphology of welded joints were analyzed by metalloscope, SEM and room temperature mechanical property test,and the high temperature healing behavior and its influence on welded joint mechanical properties were studied. The results indicated that under the effect of high temperature, the microstructure of welded joint homogenized, the partial cracks are healed,the plasticity of welded joints is improved, and the fracture mode of welded joint changes from cleavage fracture to quasi cleavage fracture. But the microhardness and shear property significantly reduce after high temperature healing treatment.
In this article, it adopted three-phase secondary rectification resistance spot welding machine and specific welding parameters to prefabricate inner cracks in 2Al2 high-strength aluminum alloy, then the inner cracks in welded joints of 2Al2 were carried out high temperature healing treatment at solution temperature(500 ℃) for 6 hours. The microstructure, crack morphology,and fracture morphology of welded joints were analyzed by metalloscope, SEM and room temperature mechanical property test,and the high temperature healing behavior and its influence on welded joint mechanical properties were studied. The results indicated that under the effect of high temperature, the microstructure of welded joint homogenized, the partial cracks are healed,the plasticity of welded joints is improved, and the fracture mode of welded joint changes from cleavage fracture to quasi cleavage fracture. But the microhardness and shear property significantly reduce after high temperature healing treatment.
引文
[1]AMBROZIAK A,KORZENIOWSKI M.Using resistance spot welding for joining aluminium elements in automotive industry[J].Archives of Civil and Mechanical Engineering,2010,10(1):5-13.
[2]龙江启,兰凤崇,陈吉清.车身轻量化与钢铝一体化结构新技术的研究进展[J].机械工程学报,2008,44(6):24-27.
[3]杨黎峰.铝合金电阻点焊熔核形成过程的数值模拟[D].长春:吉林大学材料学院,2005:1-3.
[4]HAN L,THORNTON M,BOOMER D,et al.Effect of aluminium sheet surface conditions on feasibility and quality of resistance spot welding[J].Journal of Materials Processing Technology,2010,210(8):1076-1082.
[5]CHENG Fangjie,ZHANG Jianou,HU Shengsun,et al.Numerical simulation on nugget formation and evolution in spot welding of aluminum alloy[J].Transactions of Tianjin University,2011,17(1):28-32.
[6]程方杰,单平,廉金瑞,等.铝合金电阻点焊的形核特点[J].焊接学报,2003,24(2):35-38.
[7]农琪,谢业东,金长义,等.Al-Mg-Si铝合金氩弧焊结晶裂纹形成机理的研究[J].热加工工艺,2013,42(1):205-207.
[8]胡喆,张勇,滕辉,等.金属材料裂纹愈合的研究进展与展望[J].材料导报,2014,28(17):47-52.
[9]肖亚航.金属材料裂纹自愈合的热处理试验研究[D].西安:西安理工大学材料学院,2007:40-41.
[10]张海龙,孙军.工业纯铁内部疲劳微裂纹扩散愈合过程中的形态演变[J].金属学报,2002,38(3):239-244.
[11]郭从盛,龙姝明,冯小明,等.W6Mo5Cr4V2钢内裂纹愈合过程中碳化物的生长现象[J].热加工工艺,2007,36(14):30-32.
[12]韩静涛,赵中里,张永军.大型锻件内裂纹的无塑性变形热修复技术研究[J].大型铸锻件,2006,11(4):1-3.
[13]陈宇强,易丹青,潘素平,等.温度对2024铝合金蠕变行为的影响[J].中国有色金属学报,2010,20(4):632-639.
[14]李慧中,张新明,陈明安,等.2519铝合金焊接接头的组织与性能[J].中国有色金属学报,2004,14(6):956-960.
[15]孙智,江利,应鹏展.失效分析-基础与应用[M].北京:机械工业出版社,2005:94-97.
[16]张红霞,刘晓晴,闫志峰,等.5A06铝合金焊接接头裂纹失效分析[J].材料工程,2013,58(3):27-31.
[17]赵中里,韩静涛,刘靖,等.低碳钢内裂纹热愈合时的耗散结构[J].北京科技大学学报,2008,30(3):239-243.
[18]张永军,韩静涛,刘靖,等.金属材料内部裂纹愈合形态演化过程的扩散热力学分析[J].塑性工程学报,2008,15(2):122-125.
[19]杨君刚,张海龙,孙军.工业纯镁内部疲劳裂纹的热扩散愈合[J].金属学报,2005,41(8):819-823.
[2]龙江启,兰凤崇,陈吉清.车身轻量化与钢铝一体化结构新技术的研究进展[J].机械工程学报,2008,44(6):24-27.
[3]杨黎峰.铝合金电阻点焊熔核形成过程的数值模拟[D].长春:吉林大学材料学院,2005:1-3.
[4]HAN L,THORNTON M,BOOMER D,et al.Effect of aluminium sheet surface conditions on feasibility and quality of resistance spot welding[J].Journal of Materials Processing Technology,2010,210(8):1076-1082.
[5]CHENG Fangjie,ZHANG Jianou,HU Shengsun,et al.Numerical simulation on nugget formation and evolution in spot welding of aluminum alloy[J].Transactions of Tianjin University,2011,17(1):28-32.
[6]程方杰,单平,廉金瑞,等.铝合金电阻点焊的形核特点[J].焊接学报,2003,24(2):35-38.
[7]农琪,谢业东,金长义,等.Al-Mg-Si铝合金氩弧焊结晶裂纹形成机理的研究[J].热加工工艺,2013,42(1):205-207.
[8]胡喆,张勇,滕辉,等.金属材料裂纹愈合的研究进展与展望[J].材料导报,2014,28(17):47-52.
[9]肖亚航.金属材料裂纹自愈合的热处理试验研究[D].西安:西安理工大学材料学院,2007:40-41.
[10]张海龙,孙军.工业纯铁内部疲劳微裂纹扩散愈合过程中的形态演变[J].金属学报,2002,38(3):239-244.
[11]郭从盛,龙姝明,冯小明,等.W6Mo5Cr4V2钢内裂纹愈合过程中碳化物的生长现象[J].热加工工艺,2007,36(14):30-32.
[12]韩静涛,赵中里,张永军.大型锻件内裂纹的无塑性变形热修复技术研究[J].大型铸锻件,2006,11(4):1-3.
[13]陈宇强,易丹青,潘素平,等.温度对2024铝合金蠕变行为的影响[J].中国有色金属学报,2010,20(4):632-639.
[14]李慧中,张新明,陈明安,等.2519铝合金焊接接头的组织与性能[J].中国有色金属学报,2004,14(6):956-960.
[15]孙智,江利,应鹏展.失效分析-基础与应用[M].北京:机械工业出版社,2005:94-97.
[16]张红霞,刘晓晴,闫志峰,等.5A06铝合金焊接接头裂纹失效分析[J].材料工程,2013,58(3):27-31.
[17]赵中里,韩静涛,刘靖,等.低碳钢内裂纹热愈合时的耗散结构[J].北京科技大学学报,2008,30(3):239-243.
[18]张永军,韩静涛,刘靖,等.金属材料内部裂纹愈合形态演化过程的扩散热力学分析[J].塑性工程学报,2008,15(2):122-125.
[19]杨君刚,张海龙,孙军.工业纯镁内部疲劳裂纹的热扩散愈合[J].金属学报,2005,41(8):819-823.