T形接头角接静轴肩搅拌摩擦焊三维流动特征

在T形接头横截面方向预置0.1 mm铜箔作为示踪材料,进行了角接静轴肩搅拌摩擦焊,焊后对T形接头角焊缝进行X-ray 2D透射和X-ray 3D扫描,得到了角焊缝示踪材料的2D流场和3D流场. 在前进侧热塑性材料主要以摩擦剪切为主,材料流动主要向焊接方向流动,并流向前进侧后方,后退侧材料主要以挤压为主,由于T接搅拌针螺纹的存在,使得材料整体向后退侧下方流动. 同时发现,在T接静轴肩后沿附近下方存在示踪材料"堆积区",表明T接静轴肩对附近的材料塑性流动存在一定的阻碍作用. 根据所获得的观察结果,建立了T形接头角焊缝的三维流动主要特征模型.

Three-dimensional flow characteristics of the T-joint by corner stationary shoulder friction stir welding

A 0.1mm copper foil was embeded in the transverse direction of T-joint as marker material by corner stationary shoulder friction stir welding. After welding, X-ray 2D transmission and X-ray 3D scanning were carried out on the corner weld of T-joint. 2D and 3D flow fields of the marker material of corner weld were obtained. Friction shear was dominant effect in the thermoplastic material of the advancing side. Material flow was mainly along the direction of welding, and flows through the retreating side to the advancing side. Material of the retreating side was mainly extruded. Due to the T-joint pin threads, the material flowed backward and downward as a whole. At the same time, it was found that there was an "accumulation area" of marker material at the adjacent rear of the stationary shoulder. According to the observed results, the main three-dimensional flow characteristic model of T-joint corner weld was established.