| In view of on the titanium alloy difficult to form an effective connection and the failure of the rapid failure caused by the wear of the head and other difficult problems, according to a refractory metal weld heat deficiency and other characteristics, This paper presents that back auxiliary heating method for friction stir welding of titanium alloy plate welding this method can not only play the preheat effect, the back of the heat the introduction of a certain extent can reduce friction, abrasion of a stirring head decreases indirectly increase the tool life.In this paper, On the basis of the friction stir welding related knowledge and the theory of finite element, according to characteristics of friction stir welding, for high melting point of titanium alloy back auxiliary heating stirring friction welding modeling method for coupled thermo mechanical model of the system was studied.The main work and research is listed below:1. By finite element analysis software COMSOL, geometric model of friction stir welding for coupling thermal modeling methods was built.2. Jmat Pro software calculated mixing head material H13 and TC4 titanium welding consumables and temperature-dependent thermal physical properties, which defines the temperature dependent material model.3. Numerical simulation theory, Fourier ’s law, finite element method, the basic theory of thermodynamics were used and M. Song and R. Kovacevic equations thinking about moving coordinate system were drawn, and a friction stir welding associated process parameters were established.4. For the thermal coupling model about friction stir welding process, the temperature and stress and strain distribution and other aspects of dynamic simulation were analyzed.5. The thermal effects, stress and strain fields of different friction stir welding auxiliary back with ordinary friction stir welding of high melting point metal during welding and soldering were analyzed, which recognizes the back of the auxiliary heating mix stir welding friction welding method and mechanism of the role of law is very important, theory of high-melting metal friction stir welding of new technologies to provide guidance.Analysis results show that compared with the traditional friction stir welding, friction stir welding auxiliary heating back can increase the welding heat input, improve the overall processing temperature of the weld nugget zone and welding efficiency, reinforcing material stirring sufficiency, effective control of weld residual stress, etc. advantage. |
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