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The formation reaction rate of Fe-Al intermetallic compounds was examined by dipping experiment of Fe wire into Al melt in the temperature range between 973 K and 1373 K, to determine the kinetic parameters of combustion synthesis of FeAl. A piece of Fe wire and Al powder were put into an alumina crucible, and vacuum-sealed in a quartz tube. The tube was held in an electric furnace to promote the compound formation reaction. A microstructure observation and SEM-EDX analysis of the dipped Fe wire were performed. It was found that the compound formation reaction occurred at the interface between the molten Al and the Fe wire, and a cylindrical Fe 2 Al 5 layer was formed in the wire. The thickness of the formed layer depended on the holding time and the dipping temperature. The reaction process has been similar to the combustion synthesis of FeAl intermetallic compound. Therefore, the kinetic parameters could be determined by the dipping experiment. The experimental data have been analyzed using a cylindrical model which took into account the diffusion process of Al in the Fe 2 Al 5 compound layer and chemical reaction process on the interface between Fe 2 Al 5 and Fe. The diffusion coefficient, D Al and the reaction rate constant, k c were estimated. The curves were calculated by using the obtained kinetic parameters and were in satisfactory agreement with the experimental values.

In the fields of an eco-friendly automobile, an advanced industrial machine, and a precision electronic device, controlling of vibration damping behavior of the sintering parts obtained from powder metallurgy is required. In this paper, the vibration behavior of Cu-Sn/Al 2 O 3 composite material made by powder metallurgy was investigated by a FFT analyzer.Cu, Sn, and Al 2 O 3 powders were used as initial substances. The powders were mixed and pressed into a plate shaped compact with 200 MPa. Using a vacuum furnace, the green compact was sintered at 825-1075 °C for 1 hour. By changing the mixing ratio and the sintering temperature, some kinds of the composite material plates were produced. For the composite material obtained, microstructure observation, Vickers hardness test, compression test and vibration test were performed.The composite materials were consisted from the crystal grain of 15-69 μm, and the mixed Al 2 O 3 particles were dispersed on the grain boundary. Additionally, twin crystal was also found in the composite materials. The damping coefficient of composite material depended on the mixing ratio of the raw powders and the sintering microstructure. The vibration damping behavior of the Cu-Sn/Al 2 O 3 composite material was affected by solubility element, grain boundary, dispersoid particle, and twin crystal. KEY WORDSvibration damping mechanism, damping coefficient, FFT analyzer, frequency response function, Cu-Sn/Al 2 O 3 composite material

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