Of Tc6 Titanium Alloy Superplasticity

At the present time, the formulation of the scientific method for defining process windows of difficult-to-deformation materials such as wrought superalloys has become the frontier in the field of metal forming. The use of traditional ways such as the trial-and-error and empirical method to define the process windows of the difficult-to-deforming materials can not keep pace with the rapid development of modern industry. In order to predict the deformation load and energy, the stress-strain state in the workpiece, we should have the knowledge of the constitutive relationships relating the flow-stress of deformed materials to strain, strain rat and temperature. Appropriate representation of the constitutive relationships for deformed materials is becoming increasingly important with widespread use of dynamic materials modeling and finite-element method to characterize the workpiece behavior under different conditions.Based on the experimental results of isothermal strain rate tension test, a non-linearity model of constitutive relationships for TC6 titanium alloy was established. Therefore, a new approach for establishing the constitutive relationships and determining the thermo mechanical parameters of the TC6 titanium was explored in this thesis.The superplastic behavior of TC6 titanium on the condition of different temperature and different strain rate was explored. The effects of temperature and strain rate were analyzed too.Furthermore, the tensile fracture surface of TC6 titanium was analyzed by SEM. The results have indicated that this titanium has a strong ability in superplastic, the fractographics presented big and deep dimple, so the alloy is of high toughness.