Thermal effects of ultrasonically excited grinding fluid
72 In this study, to reveal reason of improvements by ultrasonic excited fluid , the amount of grinding fluid is measured. The amount is increased by the ultrasonic vibrations in case of fluid supply is small and the grinding wheel speed is higher. Moreover, the temperature at the grinding point is measured by constructing a thermocouple, it was confirmed that the grinding heat is reduced by using the ultrasonic excited fluid. And the effect of removing a grinding heat is due to the effect of the grinding fluid volume increased to grinding point. And, longer chip obtained with ultrasonic excited fluid compared with ordinary fluid. It shows suppression of wear of the abrasive grains with ultrasonic excited fluid Normal 0 0 2 false false false EN-US JA TA 72 In this study, to reveal reason of improvements by ultrasonic excited fluid , the amount of grinding fluid is measured. The amount is increased by the ultrasonic vibrations in case of fluid supply is small and the grinding wheel speed is higher. Moreover, the temperature at the grinding point is measured by constructing a thermocouple, it was confirmed that the grinding heat is reduced by using the ultrasonic excited fluid. And the effect of removing a grinding heat is due to the effect of the grinding fluid volume increased to grinding point. And, longer chip obtained with ultrasonic excited fluid compared with ordinary fluid. It shows suppression of wear of the abrasive grains with ultrasonic excited fluid Normal 0 0 2 false false false EN-US JA TA
Experimental Verification of Effect of Grinding Fluid Excited by Ultrasonic Vibration
The grinding performance is strongly affected by grain condition. Especially loading directly raises the grinding force, reduces tool life and deteriorates accuracy of machining. In this study, ultrasonic exciter which applies vibration energy on grinding fluid was developed. The resonant frequency of 28kHz. The exciter is set between the fluid supplying nozzle and grinding wheel. The discharging grinding fluid from the nozzle is supplied to grinding wheel between the teeth of comb-shape horn. The performance is verified on surface grinding machine with vitrified WA grinding wheel. It was experimentally demonstrated that the excited grinding fluid prevented the loading and improved the surface roughness even for grinding of aluminum. And also improvement of surface roughness was recognized on alloy tool steel.
Submicron polymer structures with X-ray lithography and hot embossing
This article describes the process chain for replication of submicron structures with varying aspect ratios (AR) up to 6 in polymethylmethacrylate (PMMA) by hot embossing to show the capability of the entire LIGA process to fabricate structures with these dimensions. Therefore a 4.7 μm thick layer of MicroChem 950k PMMA A11 resist was spin-coated on a 2.3 μm Ti/TiOx membrane. It was patterned with X-ray lithography at the electron storage ring ANKA (2.5 GeV and λc ≈ 0.4 nm) at a dose of 4 kJ/cm3 using a Si3N4 membrane mask with 2 μm thick gold-absorbers. The samples were developed in GG/BDG and resulted in AR of 6–14. Subsequent nickel plating at 52°C resulted in a 200 μm thick nickel tool of 100 mm diameter, which was used to replicate slit-nozzles and columns in PMMA. Closely packed submicron cavities with AR 6 in the nickel shim were filled to 60% during hot embossing.