Study On Metallurgical Reaction Mechanism Of TA31 Titanium Alloy Hot Compress Bonding Interface

Titanium alloy has the advantages of low density,low intensity to density ratio strength,difficult to corrode,good welding performance.Nowadays,the United States,Russia and other countries have applied titanium alloys in the field of marine engineering.The connection technology is one of the key technologies in engineering applications.Because titanium is easy to nitrogen,hydrogen,oxygen,conventional electrode arc welding,gas welding,CO₂ gas shielded welding is difficult to use for TA31 titanium alloy welding.At present,the most widely used methods are tungsten argon arc welding,electron beam welding,and laser welding,but these methods are insufficient.This paper adopts a new material joining method,which can realize the connection of materials in the forging process.It is a good solid connection method.With this method,the joint can achieve good metallurgical bonding of joints,and the interface can be effectively connected to obtain excellent joints,the tensile strength of the joint can even exceed the strength of the base metal,which is more convenient and efficient than the diffusion joint.In this paper,the hot compress bonding method is used to thermally compress the TA31 titanium alloy.By changing the hot compress bonding temperature and deformation process parameters,the microstructure,morphology and interface pore evolution process of the hot compress bonding joint interface under different parameters are observed.The mechanical properties of the joints of the hot compress bonding joints were analyzed.The microstructures of the hot compress bonding joints were discussed and analyzed by metallographic microscope,SEM and EBSD.In this paper,the influence of hot compress bonding temperature and deformation on the interface microstructure is discussed.The process parameters of the hot compress bonding joint are determined by observing the interface microstructure.The process parameters of the hot compress bonding joint are analyzed,recrystallization,grain boundary migration and pore healing,and the tensile test of the hot compress bonding joints,comparing the tensile properties of the same experimental parameters,determined the optimal process parameters of the hot compress bonding,the most The interface under the good process parameters has been fully connected,the interface hole completely disappears,and the organization and performance of the interface are no different from the matrix.When the deformation temperature is 1050?and the deformation amount is35%,the mechanical performance is the best,the tensile strength reaches 1010MPa and the yield strength reaches 879MPa.The thermodynamics and kinetics of the interface healing process were analyzed.In the process of hot deformation connection,pore evolution takes place in the following three stages:the first stage,the interface contact,due to the plastic flow,the convex surface deformed and formed an isolated ellipsoidal hole at the thermal deformation joint interface;the second stage,the surface source diffusion mechanism Under the spheroidal hole,the ellipsoidal hole gradually spheroidizes;in the third stage,under the action of the interface source diffusion mechanism,the hole evolves and finally closes.After the completion of the laboratory stage,the engineering test was carried out.The 100kg grade TA31 titanium alloy ring was successfully joined,forged and rolled by the hot compress bonding joint method.The analysis of the ring parts showed that the best deformation connection parameters obtained by the laboratory were obtained.The prepared ring has uniform structure and uniform performance,meets the standard requirements,and explains the hot compress bonding method,which can realize the effective connection of TA31 titanium alloy.The surface treatment in the engineering verification process is rougher than the laboratory,and it can be efficient in the harsh field environment.Production,further indicating that the method can be universally applied,the method is more efficient and the material utilization rate is higher than the ordinary connection method.