The implantation of indium (In) onto zeolite was carried out with a low-energy mass-selected ion beam system for the possible development of novel catalysts. In ions were generated by sputtering an In₂O₃ target with Ar ions in a modified Freeman-type ion source. Ions generated in the ion source were extracted under high voltages to form mono-energetic ¹¹⁵In ion beams with the peak energy of around 500 eV. Then, the zeolite substrates were irradiated by the In ion beams. Both X-ray fluorescence and X-ray diffraction analyses revealed that the implantation of In on the zeolite surface was successful and dependent on the ion doses of In. We failed to detect the catalytic effects in the In implanted zeolite as far as at the conditions employed in the present study. However, a further study is still necessary to determine the catalytic effect of the In implanted zeolite.

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  Two-step aging behavior of an Al-10%Si-0.3%Mg alloy cast into permanent mold and then demolded at 473 K was investigated by a micro-vickers hardness measurement and scanning electron microscope observation. The peak hardness indicated almost the same value when the pre-aging temperature was R. T. and then final-aged at 423-523 K. On the other hands, positive effect of the final-aging was occurred after pre-aging at 348-423 K for a relatively long time with significantly increasing hardness in the underaging region. These tendencies were similar to the previously reported result of demolded at 773 K. In the case of the specimens were pre-aged at 373 K and 423 K for a short time without increasing hardness, negative effect of the final-aging was occurred. The behavior was different from previously reported result of demolded at 773 K. The reason of occuring the negative effect was not only difference of solute concentration with the demolding temperature, but also differences of amount of G. P. zones and clusters generated on the early stage of pre-aging at various temperatures.

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  Biomass gas is remarked as renewable energy. Therefore combustion of biomass gas has been noted, but there is a problem that heating value is low. So, the effective combustion technology has been studied for useful energy. The combustion method with using the low temperature plasma at atmospheric pressure attracts attention. It is reported that the optical emission profile at the discharge area between the electrodes shows that the plasma has fuel make CH^* radical. It is possible to enhance plasma-assisted combustion with these radicals. In this study the micro flame of methane, hydrogen and fuel gas diluted with nitrogen is formed. The flame behaviors and combustion characteristics with plasma-assisted combustion are investigated. It promotes the stability of flame. It is certified that plasma-assisted combustion is effective for biomass gas and low-grade fuels.

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  Two kinds of new Fe-Cr system alloy brazing filler, Fe-Cr-based and Fe-based, have been developed as a substitute for expensive Ni-based brazing filler in brazing of SUS304 stainless steel. Joint strength of the joints brazed with new filler were investigated and compared with the joint brazed with Ni-based brazing filler. The following results were obtained in the study.
  P-rich phases were formed because Ni in the new Fe-Cr system alloy diffused from the brazed layer to SUS304 stainless steel when joint clearance was 10 μm. When joint clearance was more than 50 μm, a finally-solidified region appeared in the brazed layer, at the same time, most of P segregated and was enriched in the finally-solidified region. It was proved that the volume fraction of P-rich phases in the finally-solidified region varied with the increase of joint clearance and joint strength decreases with the increase of the volume fraction of P-rich phases. Compared with Ni-based filler, joint strength of the joint brazed with Fe-based filler was almost equal when joint clearance was under 200 μm. On the other hand, joint strength of the joint brazed with Fe-Cr-based filler was slightly inferior regardless of joint clearance. Still, joint strength reached approximately 100 MPa. The result indicated that joint strength of the brazed joint with the Fe-Cr system alloy was strongly affected by the P addition. It is possible that promoting of joint strength can be brought by lower addition of P.

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  Recent increase in the working temperature of the electronics products caused larger thermal stress in the solder joints of the printed-circuit board. From the view point of consumer product safety, it is very important to prevent thermal fatigue crack of solder joints. In the paper, we have investigated the thermal fatigue property of the Sn-Ag-Bi-In solders after heat-cycle test from -40°C to 150°C. It was confirmed that Sn-3.5mass%Ag-0.5mass%Bi-6.0mass%In solder material is more reliable than conventional Sn-Ag-Cu solder. By the metallographic and mechanical analyses, it was also confirmed the phase transformation from γ (InSn₄) to Sn + γ at about 150°C affected the thermal fatigue properties by reducing the grain size of the solder. Thus, alloy composition should be optimized to control transformation temperature in accordance with applied conditions.

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  Sub-millimeter sized DC discharge was experimentally investigated in the range of glow region, glow-arc transition region and arc region with use of the newly developed filament electrode and high voltage power source. The filament electrode consists of the pointed tungsten electrode electrolytic-polished and filament part. The current-voltage characteristics of the micro-discharge in the current range of 15 mA to 800 mA was investigated for various curvature radii of electrode tips. And the discharge appearances and anode melt spots were observed. It was found that the arc region shifts to the smaller current by using the cathode having sharpened tip. And the micro-discharge is concentrated by using pointed cathode with heating. So, the glow mode discharge with the current of 17 mA makes melt spots at the anode surface of stainless steel.

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