Research On SLM Forming Process And Cutting Technology Of Titanium Alloy Thin-walled Parts

Titani?m alloy thin-walled parts are widely used in the aerospace field.They are manufactured by traditional cutting methods,with large cutting amount,low efficiency and serious material waste.Selective Laser Melting(SLM)can produce complex thin-walled parts that can't be produced by conventional processes,but SLM molding accuracy and surface quality often fall short of usage requirements.In this paper,SLM forming titani?m alloy thin-walled parts are used as high-quality finishing blank.The optimal molding process parameters are considered from the influence of SLM forming process on temperature field,residual stress field and deformation,and the cutting technology of SLM titani?m alloy thin-walled parts is studied.Provide some theoretical guidance for the subsequent high-quality forming and finishing of complex thin-walled parts.The specific work is as follows:(1)The transient temperature field of SLM forming process of titani?m alloy thin-walled parts was simulated by ANSYS APDL.The effects of laser power,scanning speed and thin wall thickness on the temperature field were obtained.The size of the molten pool was analyzed and the reasonable molding process parameters were determined.It laid the foundation for stress field analysis.(2)Based on the SLM transient temperature field distribution,the indirect thermal coupling is used to analyze the residual stress field and displacement field of the thin-walled SLM.The maxim?m residual stress field and deformation distribution of the thin-walled parts are obtained.The optim?m molding process parameters were determined.(3)According to the results of simulation analysis,two sets of experiments were designed to investigate the effects of different laser power and scanning speed,different wall thickness and scanning path direction on the surface morphology,microstructure,residual stress and deformation of SLM formed thin-walled parts.The residual stresses at different depths were studied by electrolytic polishing,and the residual stress and deformation of other thin-walled structural parts of SLM formed titani?m alloy were analyzed.(4)The effects of cutting parameters on the surface roughness,deformation and residual stress of SLM-formed titani?m alloy thin-walled parts were investigated by single factor experiment and orthogonal experiment.The surface morphology and defects of the specimens were analyzed.Finally,under the HyperMill software,the NC program of SLM forming titani?m alloy blade machining is simulated and processed by 5-axis linkage machine,which provides theoretical reference value for subsequent precision machining.