恒进给旋转摩擦条件下金属力学参量周期响应行为  

Periodic Variation of Torque and Axial Force of Tubular Aluminum Alloy at Constant Downward and Rotational Speed

作　　者：张雪超[1,2] 熊江涛[2] 李京龙[2] 李鹏[2] 钱锦文[2] 张赋升[2] 

机构地区：[1]西北工业大学凝固技术国家重点实验室,西安710072 [2]西北工业大学摩擦焊接陕西省重点实验室,西安710072

出　　处：《机械工程学报》2015年第2期65-70,共6页Journal of Mechanical Engineering

基　　金：国家自然科学基金(51071123;51101126);凝固技术国家重点实验室(西北工业大学)自主研究课题(43-QP-2009;31-TP-2009);西北工业大学基础研究基金(JC20120224);陕西省科技统筹创新工程计划(2012HBSZS021)资助项目

摘　　要：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。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.

关 键 词：搅拌摩擦焊 周期性 模拟试验 滑动摩擦功率 黏着摩擦功率 

分 类 号：TG402[金属学及工艺—焊接]