各向异性对焊接凝固裂纹影响规律的相场法模拟  

Phase field investigation on solidification cracking susceptibility in the molten pool under different anisotropy

作　　者：王磊[1,2] 李赫 黄勇 王克鸿[1] 周琦 WANG Lei;LI He;HUANG Yong;WANG Kehong;ZHOU Qi(Nanjing University of Technology,Nanjing,210094,China;Jiangsu Jingning Intelligent Manufacturing Co.,LTD,Jiangsu,214513,China)

机构地区：[1]南京理工大学,南京210094 [2]江苏靖宁智能制造有限公司,靖江214513

出　　处：《焊接学报》2021年第12期83-86,I0005,I0006,共6页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目(51905273);江苏省自然科学基金资助目(BK20190472)。

摘　　要：采用相场法模拟研究了各向异性对合金焊接凝固裂纹敏感性的影响规律.结果表明,随着各向异性强度的增加,枝晶尖端变得更加稳定,不易形成侧枝,枝晶间不易形成桥接,容易形成较长的液相通道.当各向异性强度较大时,金属熔体难以通过长的液相通道对受拉位置进行补给,因此容易形成裂纹.基于相场模拟结果,计算了凝固裂纹敏感性指数|dT/d(fs)^(1/2)|,发现各向异性强度较大时,|dT/d(fs)^(1/2)|的数值也较大,具有较大的凝固裂纹敏感性.综上,当合金各向异性强度越大时,具有较高的凝固裂纹敏感性.Effects of anisotropy on the solidification cracking susceptibility in the molten pool of an Al-Cu alloy are investigated using phase field modeling.The results show that the tip of dendrites becomes stable,side-branches and bridges are difficult to form,and the longer liquid channel is easily formed between dendrites with the increase of anisotropic strength.In the case of large anisotropic strength,welding tensile stresses are difficult to transfer and release through bridging,and the metal melt is also difficult to supply the tensile position through the long liquid channel,so it is easy to form cracks.Based on the simulation results,the solidification cracking susceptibility index ■ is calculated.It is found that the index is higher when the anisotropic strength is larger.In conclusion,the solidification crack sensitivity is higher when the anisotropy strength is larger.

关 键 词：各项异性 凝固裂纹 相场法 

分 类 号：TG401[金属学及工艺—焊接]