Research On Process Technology Of Isotropic Titanium Alloy Plate For Orthopedics Implantation

Titanium and titanium alloys are widely used in human bones,joints,dentistry,heart surgery,stents and other fields,and are ideal materials for surgical implants.At present,most of the titanium alloy sheets for surgical implants produced in China have anisotropy.Because surgical implant instruments continue to bear the force during clinical use,their anisotropy and stress state will increase the fracture tendency and shorten the service life.In this paper,by studying the clean titanium alloy ingot smelting process,the homogenized titanium alloy slab forging process and the isotropic titanium alloy sheet rolling process,the key technical parameters of each process are determined,and the horizontal and vertical structure are consistent.An isotropic titanium alloy sheet with equiaxed structure and close transverse and longitudinal mechanical properties.Use metallographic microscope,X-ray diffractometer,differential thermal analyzer,scanning electron microscope,electrochemical test system,and tensile testing machine to observe and detect the microstructure,phase structure,phase transition behavior,and fracture morphology of TC4 alloy in different states,Corrosion behavior and mechanical properties,and preliminary analysis of its processing mechanism,which provides a theoretical basis for industrial production.This paper uses vacuum consumable electric arc furnace smelting,through the classification and control of sponge titanium grade and particle size,and electrode pressing density control,the effects of two smelting and three smelting on the consistency and organization of titanium alloy ingots are studied.Studies have shown that the difference between the head and tail of the ingot and the middle after the third smelting is significantly reduced,and the composition uniformity is significantly better than that of the second smelting.The composition deviation of the main metal elements of AL,Fe,and V can be controlled within 0.15%;the third smelting ingot The fluctuation of N,H,O gas elements in each part of the ingot is significantly smaller than that of the secondary smelting ingot.This paper studies the effects of different forging deformation degrees and solution treatment systems on the microstructure,mechanical properties,and electrochemical properties of titanium alloy forged slabs.Studies have shown that as the degree of forging deformation increases,the alpha lath structure in the titanium alloy forged slab is refined,the strength of the forged slab increases,the hardness is basically unchanged,the plasticity first increases and then decreases,and the forging deformation is 30 %,the strength and plasticity of the forged slab are best matched;with the increase of the ageing temperature,the more the number of alpha phases precipitated,the strength first increases and then decreases,the hardness remains basically unchanged,the elongation and fracture toughness increase,and the solid When the solution aging system is quenched at 1000?+700?/8h,the slab strength and plasticity match the best,and the highest impedance and corrosion resistance are also the best in the SBF solution at 37?.This paper studies the effects of different pass rates and rolling directions on the microstructure and mechanical properties of rolled titanium alloy sheets.Studies have shown that the pass processing rate has a greater impact on the structure of the sheet.The sheet rolled with a processing rate of 15% can fully crush the forged structure.After annealing,a fine and uniform equiaxed structure is obtained;at the same time,the rolling direction has an effect on the structure of the sheet.The effect of performance is significant.The horizontal and vertical microstructures of the 90° commutation rolled plates are basically the same.They are all small equiaxed structures.The mechanical properties are basically close.This is mainly because the commutation rolling weakens the processing structure of the previous rolling process and realizes Isotropy of sheet structure and properties.The isotropic titanium alloy sheet produced in this test has been verified by the end product of the medical device manufacturer,and its static bending strength is far better than the end product processed by the conventional titanium alloy sheet;there is no failure in dynamic bending cycles of 10000000 times,reaching the dynamics of imported products of the same model Bending performance index.