Temperature Field Simulation And The Experiment Research Of Laser Welding Of TC4 Titanium Whith Aluminum Insert

With good comprehensive performance and high effective structure,such as high strength,corrosion resistance,heat resistance,Titanium alloy is widely used in the field of aerospace.Laser welding is well suited for welding structural parts that have special requirements or special materials,due to high energy density,high efficiency,high precision,easy to operate,and the resulting weld is narrow and form well,heat affected zone and welding deformation are small and other advantages.So which is received wide attention and also becoming an important means of titanium alloy welding.When high-energy laser beam acts on the surface of the titanium alloy material,the material is heated up,melt and intense evaporation may take place during a very short time.High temperature can lead to burning and evaporation of alloying elements,the loss of the alloying elements,however,will cause a significant difference in the proportion of the chemical composition between the weld and the base material.Accordingly,it changes the weld structure and also has a bad effect on the mechanical properties of titanium alloys.The investigation of the technology of titanium alloys laser welding benefits improvement of the weld quality used for aerospace structure material.It is very important to increase the national defense power.The research status in domestic and overseas is summarized,and also the posibility of welding titanium and titanium alloy is analyzed.The temperature field of the TC4 titanium alloy added aluminum sandwich is simulated through the large general simulation software ANSYS.Laser welding experiment on TC4 titanium alloy added aluminum sandwich is carried out.Firstly,a brief introduction about titanium and titanium alloy materials and the classification method of titanium and titanium alloy materials is done,then the welding characteristics of titanium alloy is analyzed and also the impact of impurity gases on titanium and titanium alloy welding performance and common alloying elements on the performance of titanium alloy welded joints is discussed respectively.Finally,the defects generated in the welding process and suppression method for them are analyzed in detail.Secondly,large general-purpose finite element software ANSYS is used to simulate temperature field formed in the process of laser butt welding of TC4 titanium alloy under the act of combination of Gaussian surface heat source and cylindrical heat source,when considering material changes with temperature thermo-physical parameters and simplifying the handling of shielding gas forced convection boundary conditions.The temperature field of laser butt welding on the TC4 titanium alloy added aluminum sandwich is analyzd.Finally,fiber laser butt welding test on TC4 titanium alloy added aluminum sandwich is conducted and the description of the overall test program is done.A brief introduction of TC4 titanium alloy materials,as well as the technical parameters performance and structure of the test equipment is made.Roughly welding parameters is obtained through basic test and the ideal welding parameters is found through Orthogonal experiment,then fiber laser butt welding test on TC4 titanium alloy added aluminum sandwich is studied by using the ideal parameters.Ultimately,the effect of TC4 titanium alloy added aluminum sandwich on fiber laser welding joint performance is discussed deeply.