This study aims to investigate machinability of carbon fiber reinforced plastic (CFRP) by grain refined Al based metal bond functionally graded grinding wheel (FGGW) containing diamond-composite particles. Diamond-composite particles which consist of nano-sized diamond particles and micro-sized green silicon carbide (GC) abrasive grains have been made by mechanofusion machine (Nobilta). The Al based metal bond FGGW was fabricated by reaction centrifugal mixed-powder (RCMP) method using mixed-powder of Al, Ti and diamond-composite particles. Since the formed Al₃Ti phase acts as grain refiner, it is expected that the grain structure of Al matrix in FGGW fabricated by RCMP method with Ti particles becomes more refined than that fabricated without Ti particles. Using the fabricated FGGW, CFRP drilling tests were conducted by gyro-driving grinding wheel system. It is found that the FGGW fabricated by RCMP method with Ti particles have fine-grained Al matrix. It is also found that optimum additive amount of Ti on the FGGW is 4~6 mass%. It is concluded that the FGGW fabricated by RCMP method with Ti particles has better machinability of CFRP by gyro-driving grinding wheel system.

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Hypothetical small scale stand-alone solar thermal power generating system has been constructed, of which thermo and electric responsiveness was predicted and clarified using improved ZnSb thermoelectric materials. The system consisted of solar collector, available primary and secondary home-use tanks, where the thermoelectric conversion module was sandwiched between these two tanks. The electric responsiveness and thermoelectric conversion efficiency was investigated. The product of overall heat transfer coefficient of the module and heat transfer area, kA affect the rate of heat transfer, period of heat exchange, the conversion efficiency and generating power. Higher kA leads to shorter completion time for heat exchange and higher thermoelectric conversion efficiency. However, the total electric energy was slightly affected by kA. The maximum energy efficiency of the system was 2.21 % and 0.413kWh at kA = 200 W/K with hot water (88.4 °C @ 0.46 m³).

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