FEM SIMULATION OF VACUUM HOT BULGE FORMINGPROCESS OF BT20 TITANIUM ALLOY CYLINDRICALWORKPIECE

摘要

Bulge forming is an innovative manufacturing process used tornproduce many industrial components. Components are bugledrnby restraining the blank in a die bearing the desired shape andrnapplying an internal hydrostatic pressure to the tube via arnliquid or solid medium. But hot bulge forming utilizes therndifference of linear expansion coefficient betweenrncomponents and dies. The research on hot bugle forming isrnlimited. However, due to the complexities involved in therndeformation process, conventional analytical studies werernable to provide only very limited knowledge on hot bulgernforming. Finite element analysis is a very powerful techniquernto study complex metal forming process. Simulations canrngive valuable information about component dimension, shape,rntemperature and stress every time. A 2-D thermo-mechanicalrncoupled elastic-plastic finite element model was developed.rnIn this model, nonlinear radiation heat transfer and thermalrnphysical properties of material depending on temperaturernwere considered. This paper carried out numerical simulationrnof hot bulge forming of BT20 titanium alloy cylindricalrnworkpiece in vacuum by using finite element softwarernMSC.Marc. The temperature field, deformation field andrnstress field of hot bulge forming of BT20 titanium alloyrncylindrical workpiece was calculated, and the correspondingrnexperiments were carried out. The simulated results agreernwell with the experimental results. This work lays arntheoretical foundation for vacuum hot bulge forming process.