CAJ | 학술논문

为了揭示搅拌摩擦焊过程中搅拌针周围金属在恒速前进下转矩、压力的响应行为，设计薄壁管状铝合金在恒速旋转和恒速下压加载下的模拟试验。研究发现转矩和压力呈周期性变化，且周期与旋转周期一致。通过计算得出滑动摩擦功率大于黏着摩擦功率并大于实际平均产热功率。进而阐明产生周期性的原因在于滑动摩擦功率大于黏着摩擦功率，可以快速积累热量使材料软化，此时压力、转矩最小；但黏着摩擦状态下材料产热效率低，因此塑性流动层金属被挤出，旋转头接触弹性层金属，此时压力、转矩最大，产热增加，使摩擦界面快速产热、材料软化甚至达到黏着，如此周而复始产生周期性。
위료게시교반마찰한과정중교반침주위금속재항속전진하전구、압력적향응행위，설계박벽관상려합금재항속선전화항속하압가재하적모의시험。연구발현전구화압력정주기성변화，차주기여선전주기일치。통과계산득출활동마찰공솔대우점착마찰공솔병대우실제평균산열공솔。진이천명산생주기성적원인재우활동마찰공솔대우점착마찰공솔，가이쾌속적루열량사재료연화，차시압력、전구최소；단점착마찰상태하재료산열효솔저，인차소성류동층금속피제출，선전두접촉탄성층금속，차시압력、전구최대，산열증가，사마찰계면쾌속산열、재료연화심지체도점착，여차주이복시산생주기성。
The periodical torque and axial force is obtained by an innovative mockup experiment for modeling the torque and forward force of pin during friction stir welding(FSW). The result shows that the cycle is equal to the time of one rotation. It can be obtained that sliding friction contributes more heat than that of sticking friction, and sliding friction power is greater than the actual average thermal power by calculating, which is the reason for the periodic variation of torque and axial force. The sliding friction accumulates heat more quickly than that of sticking friction so that the material beneath the tool is softened, now the torque and axial force are lowest. However, because lower heat production efficiency of sticking friction cannot keep the material being softened beneath the tool, the softened material will be extruded out. The tool contacts the elastic material, now the axial force and torque are highest, which lead to the sliding friction for softening the material.