The Failure Analyses And Countermeasure Study For Deep-draw Thermal Forming Of TC1 Ti Alloy Thin Plate

In the research field of new materials, except the designing, manufacturing and exploiting of new materials, it is necessary that the key technologies' researches of special forming, surface dealing, material property testing, lifetime forecasting and invaliding analyses etc. to be done. They are important methods to discover the internal features and evolution rules at different levels in manufacturing, forming and the other processing by finite element method and numerical simulation.Combining closely with the practical production of defense industry and the project of the Education Dept. of Hunan Province, invaliding analyses and countermeasure study for deep-drawing thermal forming of Ti-alloy thin plate have been done in this paper, the main fruits have been achieved as follows:Firstly, in order to provide parameters of material properties for the numerical simulation "experiments" of one rectifier internal hood deep-drawing thermal forming, the standard samples of TC1 Ti-alloy thin plate of thickness were made, the tensile tests under different temperatures and forming velocities have been done, the effects of them on the material's properties have been inquired out. Secondly, by the numerical simulation "experiments" and mechanics analyses, the effects of temperatures, forming velocities and the entering angles of mould on the products were studied. The main invaliding forms both of crinkling and crazing were simulated and analyzed, so that the technical parameters of forming, geometrical parameters of moulds were optimized. Finally, based on the tensile tests of standard samples and the numerical simulation "experiments", the improved technical scheme has been put forwarded for TC1 Ti-alloy thin plate deep-drawing thermal forming of one rectifier internal hood, including a series of countermeasures such as resetting the forming temperature and the entering angles of mould, changing the dies' materials. By a small of quantities of experimental production, the qualified rate of product has been heightened from the original about 20% to more than 80%.