森田 昇

In order to research effect on the cutting performance for aluminum alloy by mixing isopropyl alcohol (IPA) and water, the performance of IPA aqueous solution was compared with IPA and water by the sliding test, cooling test and cutting test. Consequently, it was found out that IPA aqueous solution provided the best cutting performance in the cutting fluids. The sliding test between aluminum alloys revealed that IPA aqueous solution has a function that suppresses the adhesion of aluminum alloy. It seems that the adhesion on the tool decreased by this function. The cooling test of heated test pieces showed that the cooling ability of IPA aqueous solution was higher than that of IPA. Because of high cooling ability, the chip in cutting with IPA aqueous solution mist might curl smaller than that in cutting with IPA mist.

Micro-grooves fabrication is increasing due to its importance in different technology fields, as they are required for higher functional applications such as the development of optical lens or micro channels for heat exchangers. A novel method based on the technology developed for Atomic Force Microscopes (AFM) nano-cutting is proposed, where nano-scratches are made using a micro-cantilever with a sharp tip where a normal load sufficient to remove material is applied. Instead of a rigid system to control the relative position between the tool and the workpiece, AFM nano-cutting uses a force feedback control (FBC) of the normal load on the tool edge in order to maintain a constant cutting depth during the manufacture. Due to the limited scale range of AFM machining, a larger mechanism was developed and consists on a XYZ-stage system where an elastic leaf spring type tool holder is mounted with a diamond tool chip. FBC is not yet implemented on this system; however, basic experiments (micro-grooves cutting) were performed on different materials to verify the feasibility of this setup. With these results, it is possible to analyze the relationship between static indentation tests and the normal load required during the micro-grooves fabrication. ? (2012) Trans Tech Publications, Switzerland.

Metal (copper and/or silver) ions were doped to borosilicate glass surface by electric field-assisted ion exchange method. Doped ions changed the optical characteristics of glass material. For example, the optical absorption of glass remarkably increased in ultraviolet range. In order to understand the relationship between metal configuration in glass substrate and their optical characteristics, metal-doped areas were observed by transmission electron microscope (TEM). As a result, it was found that the doped ions aggregated and formed nanometer-sized (2 〜6 nm) metal particles. Therefore, it was suggested that the change in optical characteristics was caused by the light scattering and absorption by metal nanoparticles.

A laser forward transfer technique of gold nanoparticles (GNPs) deposited on glass substrates to silicon wafers and periodic patterning of transferred GNPs is demonstrated. Gold colloidal solution was prepared by citric acid reduction method. The GNPs were deposited by immersing glass substrates derivatized with (3-aminopropyl) trimethoxysilane (APTMS) in the gold colloidal solution for 0.5 h - 3 h. Dispersed or aggregated GNPs were deposited by using Gold colloidal solution with different concentrations. The glass substrate deposited with the GNPs was placed on a Si substrate. The GNPs deposited side was faced to the Si substrate. Then GNPs were illuminated with the second harmonic wave of Nd: YAG laser through the glass, as a result the gold nanoparticles were transferred to the Si substrate. The GNPs deposited on the silicon surface was sphere and dispersed, nevertheless, they were aggregated on the glass surface before transferring by the laser illumination. After the illumination of the Nd: YAG laser to the silicon surface with the GNPs, the periodic deposition of Au was observed. The periodic spacing of the Au were depended on the wavelength and incident angle of the laser beam.

The shape control of laser-drilled holes was studied with the laser drilling machine that controls laser pulses and stages. Borosilicate glass was drilled with the forth harmonic of nanosecond Nd:YVO_4 laser. Laser illumination with changing defocus distance achieved the change of the diameters from 10μm to 24μm at the depth of 200 μm.

In this study, we examined the deposition of titanium dioxide powders on the surface of a polypropylene sheets byLaser-Induced Powder Jet Implantation (LIPJI). Jetting the powders to the sheets melted by laser illumination enabled the deposition of the powders on the surface. In addition, methylene blue decolorization confirmed photocatalytic reaction.