Study On The Electron Beam Welding Process For TC4 Titanium Alloy Booster Stage Stator Assembly

Supercharged stator assembly is a key component of universiade engine.It requires very high manufacturing,welding precision and precision stability,especially in the key factors such as shape and dimension of outer ring casing inner runner space after welding,inner ring runner shape and dimension,runner window size,blade chord tangent angle and so on.The control of welding quality and dimension after welding has been a bottleneck in the domestic engine industry.In this paper,the finite element model of electron beam welding process for TC4 titanium alloy supercharged stator assembly is established.The influence of different welding sequence on the deformation after welding is studied.The typical welding process of supercharged stator assembly is determined.And,the high precision assembly/welding tooling,electron beam welding baffle and post-weld heat treatment calibration tool are designed.Based on that,the electron beam welding parameters of stator assembly are optimized.According to the engineering practice,the typical welding process routine of TC4 titanium alloy supercharged stator assembly is as follow: cleaning before welding,selecting and assembling blades,argon arc positioning welding,electron beam welding,welding seam cleaning,post-weld heat treatment;Besides,the high-precision assembly/welding tooling of zero-level stator assembly and the electron beam welding baffle are designed,and the post-weld heat treatment calibration tool made of 1Cr18Ni9 Ti is manufactured to ensure the welding quality of assembly.The test results show that,by changing the welding sequence of stator assembly to 180? sectionalized symmetric welding,meanwhile,increasing the acceleration voltage,decreasing the welding speed and welding current,changing the waveform,amplitude and frequency of electron beam scanning,the weld forming quality of stator assembly is obviously improved,the residual height of weld back is reduced,the qualified rate of blade angle and height different value after welding is raised.For the zero-stage stator assembly,twice upward slope welding and 180? symmetrical high-speed welding are adopted.By reducing the acceleration voltage,increasing the welding speed and welding current,changing the waveform,amplitude and frequency of electron beam scanning,the welding heat output is greatly reduced,the welding deformation of parts is effectively reduced,and the better weld quality is obtained.