Research On Laser Deposition Repairing Of Titanium Alloy Thin-Wall Structure Based On Numerical Simulation

The laser deposition manufacturing(LDM)technology uses the powder and laser synchronization method to melt the metal powder through the laser and rapidly solidify layer by layer deposition.The complex geometry structures metal parts can be manufactured directly by it.Due to the features such as direct manufacturing,LDM has been widely used in high-end manufacturing fields such as aviation and aerospace.Titanium alloys are commonly used as metal materials in the manufacture of aerospace and aerospace components.Titanium alloys are difficult to machine and the parts structure are complex.Therefore,it is very difficult for conventional manufacturing methods to process titanium alloy parts.The laser deposition manufacturing technology can quickly manufacture titanium alloy parts and repair damaged titanium alloy parts,and has a wide range of application prospects.Laser deposition manufacturing process is accompanied by uneven temperature gradient distribution,which brings huge residual stress,causing cracks and deformation defects.Therefore,in view of the defects in the process of laser deposition,the distribution of temperature stress in the process of deposition is analyzed with the help of numerical simulation,and the mechanism of deformation is revealed.Aiming at typical damage titanium alloy parts,laser deposition repair and energy regulation are studied.For the problem of difficulty in real-time monitoring of temperature during laser deposition forming.Based on the theory of heat transfer and the theory of thermal elastoplasticity,using ABAQUS finite element software to establish a single-channel laser deposition numerical simulation model,while taking into account the Ti-6A1-4V material physical and mechanical properties parameters.The single-channel laser deposition Ti-6A1-4V temperature and stress numerical simulation was realized by using the method of birth and death,and the experiment was verified.Based on the numerical simulation model,the influence of laser deposition process parameters on the distribution of temperature and stress was studied.Considering the dilution rate and residual stress comprehensively,the best process parameters of Ti-6A1-4V titanium alloy laser deposition were obtained,which provided guidance for laser deposition and repair of subsequent Ti-6A1-4V thin-walled parts.Laser deposition manufacturing repair technology was used to repair the thin wall structure of typical titanium alloys,and the repair quality was analyzed.A numerical simulation model for the laser deposition recovery of titanium alloy thin-walled structures was established,revealing the changes in deformation stress and deformation and the deformation mechanism of thin-walled structures.It provides theoretical guidance for the repair of laser stress and deformation control of thin-wall titanium alloy structures.For the typical titanium alloy thin-wall structure photodeposition repair deformation problem.The preheating treatment and the addition of restraint strategies were used to control the stress and deformation,and the effect of the stress was analyzed.Finally,the method of laser deposition repair deformation control of titanium alloy thin-walled structures is optimized.