搅拌摩擦焊材料塑性流动可视化研究现状

Research progress of plastic flow visualization technique of friction stir welding

综述近年来国内外搅拌摩擦焊塑性流动可视化技术的研究现状,分析各种方法的基本原理及优缺点。研究现状表明:异种材料金相组织显示法可以观察到焊缝接头宏观流动,而对搅拌摩擦焊塑性流动的细节无法获取;彩泥法颜色鲜明,易于观察,但其是非晶体材料,故只能在一定程度上模拟搅拌摩擦焊的塑性流动状况;标识材料示踪法是搅拌摩擦焊材料塑性流动可视化工作的主要手段,其选用原则、焊接过程及焊后采用的可视化手段仍需进一步深入探讨;数值模拟是一种高效、低成本的研究方法,其具备再现焊接过程的能力,模拟过程的边界值、搅拌头的描述等方面需要进一步深入探讨。

Plastic flow visualization techniques of friction stir welding in recent years are reviewed, and the basic principles, advantages and disadvantages of different methods are analysed. The investigation shows that macroscopic vortex-shaped layer in weld joints can be observed by microstructure observation of dissimilar materials welding, while other detail of metal flow can not be revealed. Plasticine simulation is a relatively simple technique to study material flow during friction stir welding, but plasticine is an amorphous material, and can roughly reflect the material flow during friction stir welding. Tracer method of marking material is a popular technique for studying material flow of friction stir welding, while the selection principle of marking material, visualization techniques during and after welding process still require further discussions. Numerical simulation is a high-efficiency and low-cost research technique, and can reappear the welding process, however, some problems such as the boundary value of simulation process and the description of stirring head deserve to be discussed.