| Summary: | 碩士 === 國立虎尾科技大學 === 創意工程與精密科技研究所 === 98 === The current study aims to investigate the thermal differential deep drawing and sinking process. Firstly, an approach based on the mechanical properties of an AISI-1045 was applied to construct flow stress curve and the anisotropy index. Then, the Taguchi method and DEFORM-3D finite element method were combined to conduct the optimization design of process parameters, which included the die profile parameters such as punch radius, die radius, punch angle and die clearance. Based on those optimal process parameters, the VISI die design commercial code and die design theory were used for the die design. Furthermore, in order to explore the influence of blank forming temperature, friction factor, and punch speed forming parameters on the forming load and the strain in the deep drawing and sinking parts, the finite element software was employed to simulate the thermal differential deep drawing and sinking forming process.
Study showed that the tensile test combining with strain gauge and grid etching could establish AISI-1045 stamping database, and enhance better agreement between the experiment and the simulation results. As for the die geometry optimization design, the best deep drawing thickness could be attained when the deep drawing punch radius is 3 mm, die radius 10 mm and die clearance 1.1 t. And when the sinking process punch entrance radius is 3 mm, punch entrance bevel 45°, and sinking stroke 11 mm, the best necking aperture could be generated.
Through the investigation of other parameters, such as the forming temperature, punch speed, and the friction factor, it was found that higher temperature and punch speed in thermal differential drawing process can relatively lower the drawing load, and the friction factor size for the load has the enlargement tendency. When the thermal differential deep drawing forming temperature and punch speed are higher, the strain at the deep drawing cylinder round corner is effectively reduced, further slowing down the thinning of the round corner. In addition, when the forming temperature and punch speed are higher in the thermal differential sinking, the sinking load can be relatively reduced, and the friction factor size of the load increases. The effective strain at sinking is slower when the forming temperature is higher. The punch speed has not much influence on the effective strain, and friction will increase the effective strain.
As for the experiment, deep drawings are performed to verify the feasibility of simulation and design. The experimental results showed that the cylindrical drawn cup derived at the forming temperature of 700 ℃ will appear rupture; forming by simulation is possible, mainly because the temperature gradient set up by simulation could not be reached by the heating equipment.
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