Titanium Stir Friction Welding Process And The Analysis Of Temperature Field

Friction stir welding (FSW) is a relatively new solid state joining process. It is said to be "the most revolutionary joining method after laser welding". Compared with the conventional welding processes, friction stir welds not only get batter joint, but can be used in various kinds of materials, which very hard to complete in conventional welding processes, such as high-strength aluminum, mild steel and titanium alloy etc. In order to hold the advanced joining process, people make a lot of FSW experiments on various situations.In the study, we select TC4 as the object, which will be applied widely. During the processing, we can get good joint by change normal force, rotate speed and welding speed, then, analyze the samples to get knowledge about FSW. The result shows that the weld region of defect-free weld of TC4 displayed four microstructure distinct regions: stir zone, thermo-mechanically affected zone, heat affected zone, base material. For heat affecting, the β grain in HAZ growth; there are a lot of exceeded a grain in the TMAZ, for the dynamic recrystallization resulted by heat and plastic yield; the temperature of SZ exceeded the β-transus temperature, its microstructure is prior β and transformed β, which was resulted by intense deformation caused by probe's stir.In order to know the FSW process profundity, we made a temperature finite element analysis, after experiment. Simulation can provide academic base and reference for study. Temperature distribution is an important content of FSW research, In the study, simulation was carried out by finite element software ANSYS, whose APDL parameterized program function was used. Transient tem analysis was transferred to steady-state analysis, which occurred in short time. In the simulation, the tool's move was replaced by moving coordinate system. The heat source includes frictional heat between the tool and workpiece and interacting of probe and workpiece, and the heat caused by metal's plastic yield was ignore. To analyze, contrast and validate the result of simulation and experiment, it shows that model is accordant with real process.