Finite Element Simulation Study On Powder Metallurgy HIP Process Of Ti₂AlNb Alloy

With the rapid development of technologies such as aerospace,vehicle and ship,the performance requirements for alloy parts are getting higher and higher.Especially in the field of high temperature structural materials,the traditional Nickel-based hightemperature alloy already cannot satisfy the needs of reality,but Ti2AlNb alloy,with the good performance of high temperature corrosion resistance,high specific strength,excellent mechanical properties,has been paid more and more attention in the field of high temperature materials.However,adopting traditional machining of Ti2AlNb alloy is difficult due to its high hardness,but more complex alloy components can be produced directly by Hot Isostatic Pressing(HIP)process,which is a near net shape technology.The purpose of this paper is to understand the whole process of Ti2AlNb alloy part HIP through finite element simulation.First of all,the flow law of pre alloy powder under the HIP this paper is found through the use of the finite element software Abaqus on hot isostatic pressing process research of Ti2AlNb alloy powder,and real-time virtual dynamic observation of HIP process,as well as temperature,pressure,shape factor,coating thickness,initial relative density was observed on the HIP process ware HIP process is optimized by the influence of density,thus,an optimal process route of HIP process was eventually found.Further,the accuracy of the optimal process route was verified by the finite element simulation of a typical annular component with the best HIP process condition obtained by Abaqus software.Secondly,the thermal deformation behavior of Ti2AlNb alloy at high temperature was studied,the constitutive equation of the alloy at high temperature was fitted,and the thermal machining diagram of the alloy at high temperature was established.According to the result of the current study,the main results were as follows:Ti2AlNb pre-alloy powder in the process of HIP,the relative density of powder body presents an s-shaped growth with the HIP process.The higher the temperature,the greater the pressure,the degree of densification of powder body is much higher.Bag is thick,the shielding effect produced by hot isostatic pressing process,the more obvious,the deformation and densification of powder body had an obvious effect;Through different shape factor comparison,were(blank)found at the time of pressure coefficient of 8 powder body relatively uniform density and the stress and strain distribution;The powder has been a completely densification,when the initial relative density of powder is 0.68.the best way of HIP process:under the condition of temperature 1030℃ and pressure 130 MPa,the level of densification ware is highest through HIP.Best hot working route of Ti2AlNb alloy is as follows:temperature 1000～1050℃,strain rate 0.001～1 s-1 the best hot working range for the alloy.The stress-strain curve of alloy is obtained by high temperature hot,and the constitutive equation is fit out according to the hyperbolic sine function fitting out Ti2AlNb alloy in 900～1200℃,the range of 0.001～1 s-1 strain rate:...