Effect of heat treatment in the cooling rate of TC4 titanium plate performance

First observe different temperature air-cooled . 1000 ℃ in the β -phase region has TC4 titanium alloy , and its air-cooled tissue equivalent β annealing organization . Microstructure in coarse grain boundaries and β original β grain interior needles α, this time corresponds to a high tensile strength and low tensile ductility . 950 ℃ and 930 ℃ in the upper two phase region TC4 titanium alloy specimens get different proportions of primary α phase and β phase in the heat , in the subsequent air cooling in the β -phase precipitates α transformation occurred more than a plastic needle in the microstructure primary α phase and β phase are equiaxed .surgical implant titanium Apparently born in the heat of the amount of α -phase sample 930 ℃ some more , this time with a tensile strength of about 1000 ℃ sample , but the tensile ductility and toughness is almost the highest. 830 ℃ in the lower part of the two-phase region TC4 titanium alloy , a large number of primary α phase , so that the change is not visible in the microstructure of β -phase morphology, see only the intergranular phase α β isometric born between this when tensile strength decreased slightly, but higher tensile ductility .
In addition , TC4 titanium original state before the heat treatment process on microstructure and mechanical properties of tissue microstructure after heat treatment has a great impact. On TC4 titanium alloy, can be roughly divided into two categories the original tissue . One is the above-mentioned organizations like furnace cooling after 1000 ℃, that basket -like tissue , which is produced at temperatures above the phase transition point blank firing or a small amount of deformation after processing ; other is α and β of equiaxed α or the β plus transformed tissue , which is above the phase transition point or a large amount of deformation in the process for the phase transformation point different deformations produced by processing . Experiments show that the former is difficult to change the subsequent heat treatment . Tensile ductility of this organization, annealing (700-800 ℃, heat 1 hour air-cooled ) , the ratio is usually axis ( transformation of the Canadian -born α β) organization , reduction rate, but the high temperature creep resistance and fracture toughness and high thermal salt stress corrosion resistance.
Clearly, the performance of TC4 titanium alloy is varied ,titanium whole distributor in order to ensure that the final product to get the desired performance and stability, should be considering the original tissue and heat treatment process.