| dc.description.abstract | This study proposes a conceptual design of M1.2 micro-form taps with Unequal Fluteless Spacing (UFS). The common form tap has four arc edges of equal length, while the UFS form tap has eight arc edges of unequal length and four straight edges of equal. The concept of UFS can reduce the processing torque of the form tap and increase its life. In order to explore the effect of reducing the torque, this study applies the UFS form tap to the processing experiment of internal threads. The UFS form tap and workpiece materials used in the experiment are tungsten carbide and aluminum alloy 7075-T651, respectively. The processing parameters (or control variables) of the UFS form tap considered in this study are the lower aperture, the speed of the rotation and the concentration of the lubrication. The central composite design method is used to plan and conduct experiments to establish the regression model of the maximum torque and the fill rate of the internal thread. The regression model is used to complete the purpose of parameter optimization design. In addition, this study also discusses the influence of the processing parameters on the torque of the internal thread forming and the fill rate of the internal thread. Regression models of maximum torque and the fill rate of the internal thread were established for statistical analysis and analysis of variance (ANOVA) of experimental results using the statistical software Minitab, and were used in the parameter optimization design. In this study, the objective function is to take the desired maximum torque as the objective function, and the fill rate of internal thread is the limiting condition to optimization design, in order to obtain the optimized fill rate of internal thread and maximum torque. In addition, this study conducts experimental verification based on the results of the processing parameters optimization design, and the results show that the regression model of maximum torque and the fill rate of the internal thread have good predictability. | en_US |