CAJ | 학술논문

逆向差速搅拌摩擦焊接是一种搅拌针与轴肩分离并逆向差速旋转的搅拌摩擦焊接新工艺。为了实现逆向差速搅拌摩擦焊接的工艺优化，掌握焊接工艺参数对接头组织和性能的影响规律，需要深入研究这一新工艺涉及的热物理机制。综合考虑焊接过程中的摩擦产热和塑性变形做功作用，建立逆向差速搅拌摩擦焊接过程中材料流动与热分布的三维耦合数理模型，研究焊接过程中温度分布特征、材料流动规律、搅拌头附近的应变速率分布以及黏度分布情况，获取焊接过程中搅拌头附近的材料流动规律、应变速率以及黏度分布的规律。对比分析逆向差速搅拌摩擦焊与常规搅拌摩擦焊在温度分布、材料流动以及搅拌头附近应变速率和黏度分布的差异。焊缝横断面的数值模拟结果与试验实测结果基本吻合。
역향차속교반마찰한접시일충교반침여축견분리병역향차속선전적교반마찰한접신공예。위료실현역향차속교반마찰한접적공예우화，장악한접공예삼수대접두조직화성능적영향규률，수요심입연구저일신공예섭급적열물리궤제。종합고필한접과정중적마찰산열화소성변형주공작용，건립역향차속교반마찰한접과정중재료류동여열분포적삼유우합수리모형，연구한접과정중온도분포특정、재료류동규률、교반두부근적응변속솔분포이급점도분포정황，획취한접과정중교반두부근적재료류동규률、응변속솔이급점도분포적규률。대비분석역향차속교반마찰한여상규교반마찰한재온도분포、재료류동이급교반두부근응변속솔화점도분포적차이。한봉횡단면적수치모의결과여시험실측결과기본문합。
Reverse dual-rotation friction stir welding (RDR-FSW) is a novel variant of FSW process in which the tool pin and the assisted shoulder rotate reversely. Modeling and simulating the material flow and heat transfer phenomena is of great significance to completely understand the process mechanism. A three-dimensional model of RDR-FSW process is developed to conduct the numerical simulation of material flow and temperature profile during the process. Plastic deformation heat generation rate and friction heat generation rate during the process are both considered. The plastic material flow velocity fields, streamlines, strain rate and viscosity fields near the tool are studied. The predicted shape and size of thermal-mechanically affected zone(TMAZ) match well with the experimentally measured ones.