Study On Heat Treatment Process Of TC16 Titanium Alloy Forging Bar

TC16 is a martensitic?+?two-phase titanium alloy,?stabilization coefficient K_? =0.8,the maximum cross-section thickness of fully hardened can reach 60 mm,can manufacture large-size fasteners.The research objects in the literature are basically rods and wires with a size of ?20 mm or less,and rolling diameters are used.It is rare to study the heat treatment process of forged bars.Combined with the need for engineering optimization of the stability of this type of alloy,the heat treatment process of forged TC16 titanium alloy bars was carried out.In this paper,the forged titanium TC16 titanium alloy bar with a diameter of ?50 mm is taken as the research object,and two types of heat treatment of solution and solution aging are carried out at different temperatures and cooling methods.The optical metallographic structure analysis,scanning electron microscope fracture analysis,and tensile tests,cold forged tests and shear tests were conducted to study the effects of different heat treatment processes on the microstructure and mechanical properties of the alloy.A preliminary study on the correlation of the mechanical properties of forged TC16 titanium alloy bars is provided to provide theoretical basis and data support for the engineering production of the alloy.research shows:The wrought TC16 titanium alloy bar was gradually transformed from an equiaxed structure into a fine-layered Widmanstatten structure after 780?-900?solution air cooling,and the yield ratio was 0.85-0.87.After 820?solution air cooling,the strength matching with plasticity is better;after forging TC16 titanium alloy bar is solution-cooled at 780?-900?,the structure gradually changes from equiaxed structure to supersaturated martensite,the yield strength ratio is 0.22-0.64,the yield strength is solid The effect of solution temperature is obvious,but the plasticity index does not change much;after the forged TC16 titanium alloy rod is cooled in the solution furnace at 780?-900?,the structure gradually changes from the equiaxed structure to the coarse-grained Wei structure,0.87-0.95,As the solution temperature increases,the strength increases,and the plasticity decreases.When the TC16 forging rod is solution aged,the strength and plasticity match is optimal under the system of820?×2 h+WQ+560?×8 h+AC.For the correlation study of mechanical properties,the shear strength?of the TC16forging bar in the double-shear state increases with the increase of the tensile strength R_m in the tensile state,and the shear strength in the double-shear state and the tensile strength ratio is irrelevant.Compared with the solution aging state of the TC16 forging bar,the ratio of forging redunction the solution state is relatively stable,which is less affected by temperature and is more conducive to forming.Using TC16's low-modulus properties after solution to match a reasonable strength index can be another recommended solution for manufacturing low-modulus medical titanium alloys,which may effectively reduce the manufacturing cost of such titanium alloys.