| Summary: | 碩士 === 國立虎尾科技大學 === 機械與電腦輔助工程系碩士班 === 107 === Both domestic and foreign tool industries have to design different tool geometries for cutting different materials. However, the design of the tool geometry belongs to the know-how of every tool manufacturer and it is based on the mechanical properties of materials. The tool geometry generally refers to the rake angle, relief angle, and helix angle. The mechanical properties mainly focus on the yield strength, tensile strength, shear strength, hardness, thermal conductivity, Young's modulus, and toughness.
The wedge angle of cutting tools should increase with the gain of hardness and strength of materials to resist the high hardness and strength of the material. The design of the normal relief angle is related to Young's modulus and toughness of the material, mainly to avoid springback effect during the cutting process. In this thesis, the wedge angle and the normal relief angle of the cutting tool were designed according to the mechanical properties of eight different materials (quenched SKD61, annealed SKD61, quenched S45C, annealed S45C, NAK80, SUS316L, SUS304, and Ti-6Al-4V). The flatness of the cutting edges was measured by the toolmaker microscope to determine the situations of the flank wear. Database consisting the mechanical properties of different materials along with the wedge angle and the normal relief angle of cutting tools were created and introduced to the Abductory Induction Mechanism (AIM) polynomial network for predictive analysis. To verify the accuracy of the system, data of the mechanical properties of two untested materials (SCM440 and SUS420) was loaded into the AIM polynomial network for prediction. The experimental prediction for the wedge angle and the normal relief angle of SCM440 were 76.47 degrees and 6.25 degrees, respectively, whereas for the material case of SUS420, the wedge angle and the normal relief angle predicted to be 68.72 degrees and 3.46 degrees, respectively. After the experimental cutting, the flatness of the cutting edges is in the range of 4 μm, which indicated the flank is in the normal cutting condition.
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