Study On Hot Deformation Behavior And Processing Map Of Titanium Alloy Ti-B25

With the development in the field of ship,the demand for high strength and corrosion resistance materials also continued to rise,high strength titanium alloy is the most ideal material.High strength ? titanium alloy which not only has good cold and hot processing performance,but also achieve the desired strength and plasticity to match,is the main research direction of high strength titanium alloy in domestic and foreign.In order to promote the use of titanium alloy on ship and meet the demand of ship communication system for titanium alloy pipe,studying on thermal deformation behavior and microstructure evolution is the research object in this paper,according to the thermal simulation compression test.Technological parameters are optimized by establishing constitutive equation and machining drawings;To carrying out finite element simulation of tube extrusion process by the Deform;To carrying out extruding tubes with optimized parameters.Primary contents can be drawn as follows:(1)Ti-B25 titanium alloy is sensitivity to the deformation temperature and strain rate.According to stress-strain curve,we found out two softening mechanisms(dynamic recovery and dynamic recrystallization)in the process of deformation.(2)Established the constitutive model based on Arrhenius equation with parameters Z.The relationship between flow stress and deformation parameters was described.The constitutive equation has good accuracy.(3)The processing map of titanium alloy under the experimental conditions was established.In the stable region,the alpha phase spheroidization and dynamic recrystallization had appeared in the material;In the instability region,rheological instability and local plastic flow had appeared in the material.(4)To carrying out finite element simulation of tube extrusion process with optimized parameters.Prepare for pipe extrusion by analysis of stress field,strain field and temperature field.(5)Under the 900?,0.1s-1 condition,the extruded tube has a good surface quality.Recrystallized grains were found in the tissues.Original grains in which the plastic deformation occurred has undergone moderate growth.After extrusion and aging treatment(830?/1h+600?/8h),the extruded tube has got the desired strength and plasticity to match,which meet the application requirements of antenna tube.