Performance Evaluation Of Damage Tolerance-based Titanium Alloy Processing

The current damage tolerance design approach has become the universal norms of modern aircraft design. Titanium Alloy TC4-DT precisely in order to meet China's new aircraft damage tolerance design requirements by our own research and development of damage tolerance-type titanium alloys. In this paper, titanium alloy TC4-DT as the research object, mainly from mechanical processing(mainly from the residual stress distribution) and thermal processing performance(high temperature compressive properties) of its processing performance study.Main tasks are as follows:1. The use of finite element software Abaqus, with Johnson-Cook model for the material constitutive model to establish titanium alloy TC4-DT finite element model of cutting. Use cutting model to simulate cutting process with cutting feed rate per tooth, cutting speed, cutting width, cutting depth change.2. Were to change the amount of feed per tooth, cutting depth, cutting width, cutting speed, the four cutting parameters of single-factor experiments. The data obtained by experiment and simulation results were analyzed.3. In this thesis, the compression deformation behaviors of TC4 titanium alloy have been studied by compress test at high temperature. The true stress-true strain curves of TC4 alloy of compression test under different conditions (deformation temperature, strain rate) are discussed.4. Research on hot deformation parameters impact on the microstructure and performance of TC4-DT alloy. In-depth study TC4-DT alloy microstructure evolution, a more systematic study of the deformation parameters impact on the organization.Through the above work, draw the following conclusions:1. Obtained from the simulation results: With the increase in cutting width, the workpiece surface residual stress increases first and then experienced a reduction process. With the depth of cut, feed rate per tooth is increasing, and processed parts surface residual stress values continue to grow. With the increase in cutting speed, workpiece surface residual stress significantly reduced.2. Simulation values and experimental error of less and the trend of residual stress consistent. The result proved that the cutting model can be used for residual stress analysis.3. By high temperature compression tests to the results and to establish the material constitutive equation. Provide a mathematical model of the material for finite element simulation.4. Temperature of 890℃, strain rate 1×10-3S-1 is the best high-temperature compression condition for titanium alloy TC4-DT. Under this condition, the flow stress is low, and the resulting compression of plastic well-organized, uniform fine.