Study On The Effect Of EB Furnace Melting TA10 Alloy Electron Gun Process Conditions On Ingot Solidification Process

TA10 titanium alloy(Ti-0.3Mo-0.8Ni)is a near-α alloy with excellent resistance to crevice corrosion.In addition to its excellent corrosion resistance,it also exhibits excellent process formability and welding performance.Therefore,this alloy is widely used in fields such as petrochemical,marine engineering,and aerospace.In recent years,with the advancement of technology,higher technical requirements have been put forward for the production of titanium and titanium alloys.Because the electron beam cold hearth melting(EBCHM)technology can effectively remove high and low density inclusions in titanium and titanium alloys,it is currently the mainstream advanced technology for melting titanium and titanium alloy ingots.However,electron beam cold hearth melting is carried out in a high temperature and high vacuum environment,and the melting process setting during the melting process will have a great impact on the quality of the ingot production.In addition,some alloy elements with high saturated vapor pressure in titanium and titanium alloys are prone to volatilize,resulting in uneven composition of the ingot.In this study,numerical simulation software ANSYS and Pro CAST were used to investigate the solidification process of TA10 titanium alloy round ingots during the electron beam cold hearth melting,exploring the flow field,molten pool evolution,temperature field,and stress distribution during the solidification process.This paper first simulated the flow field and melt pool evolution during the solidification process of TA10,and found that increasing the casting temperature and speed both enhance the fluidity of the melt inside the melt pool and increase the depth of the melt pool.Among them,the casting speed has the most significant effect on the stirring of the melt and the depth of the melt pool.However,excessive casting speed will widen the mushy zone,which will make the obtained ingot more prone to defects.Next,by loading a Gaussian heat source on the surface of the melt pool to approximate the scanning of the electron beam,the relationship between different process parameters(casting temperature and casting speed)and the surface temperature of the melt pool under the rated electron beam process conditions was explored.Through the study,it was found that appropriately increasing the casting temperature and speed can reduce the energy loss of the electron beam and reduce the element volatilization caused by the electron beam scanning by increasing the casting temperature and casting speed.Based on the above research,the optimal process parameters for the melting of TA10 studied in this paper were determined: the casting temperature was 2273 K,and the casting speed was 0.0295 m/s.This paper also investigates the effect of electron beam scanning on the melt pool surface temperature under different process conditions(electron gun power,electron beam diameter,and electron beam frequency).This study aims to suppress element volatilization and ensure the stability of ingot chemical composition by controlling the temperature,and to provide a scientific and theoretical basis for the setting of process parameters in actual production.It is found that with the increase of electron gun power,the local superheating phenomenon in the central region becomes especially obvious,and the temperature fluctuation on the surface of the melt pool becomes more and more intense;however,this phenomenon will gradually disappear with the increase of the scanning electron beam diameter,so when a large power is elected in the actual production,the temperature field on the surface of the melt pool can be kept uniform by increasing the electron beam diameter;when the electron beam frequency reaches After the electron beam frequency reaches more than 10 Hz,the temperature change on the surface of the melt pool will stabilize,and the temperature fluctuation will be greatly reduced and finally reach stability.In addition,this paper also explores the influence law of the scanning electron beam on the evolution of the melt pool.In order to improve the quality of the cast ingots,this article also studied the distribution of TA10 round ingot stress under different process parameters(casting temperature and casting speed).The simulation results showed that the region with the maximum equivalent stress was mainly concentrated inside the crystallizer and at the bottom of the ingot.Compared with casting temperature,casting speed had a smaller impact on the stress field.As the casting speed increased,the equivalent stress on the surface of the ingot gradually decreased.