|Budget Amount *help
¥31,000,000 (Direct Cost : ¥31,000,000)
Fiscal Year 1995 : ¥8,100,000 (Direct Cost : ¥8,100,000)
Fiscal Year 1994 : ¥12,500,000 (Direct Cost : ¥12,500,000)
Fiscal Year 1993 : ¥10,400,000 (Direct Cost : ¥10,400,000)
This study aimed to understand the high-speed and minute phenomena in energy beam machining and to know the dominating factors needed to attain the higher precision. The followings are the main results :
Heat transfer in electrical discharge machining
First, the energy distribution into electrodes was obtained from the inverse problem solution, and it was found that the energy distribution into the anode is greater than that into the cathode. However, the material removal rate of the anode is higher than that of the cathode. This is because the precipitation of carbon onto the anode surface protects the anode from wear. Secondly, the time required to deionize the plasma generated by a pulse discharge and recover the dielectric breakdown strength of the discharge gap during the pulse interval was calculated by the finite difference method, and the calculated results were compared with the experimental results. It was found that when materials with low thermal diffusivity are used as the e
lectrodes, the time required to deionized the plasma is long and so that the process is likely to get unstable.
Pit formation process in a polymer film by laser irradiation
Pit formation process was investigated both experimentally and numerically. In the experiments, various lasers, which were semiconductor, argon, excimer, and fourth harmonic YAG lasers, were used in order to examine the effect of the beam wavelength. In the thermal process caused by the semiconductor laser and the argon laser, the increase in irradiated heat flux and an absorption coefficient of the polymer film promoted the pit formation. In the numerical analysis using the finite element method, the effect of beam absorption model and beam intensity profile affected the pit surface deformation by the effect of the Marangoni force. In the non-thermal process caused by the excimer laser and the YAG laser, irradiated ultra-violet beam caused laser ablation process. For this case, the removed volume and the irradiated energy showed linear relation. The pit surface morphology showed the dependency on a material, tensile history, and an irradiation condition.