Fabrication of Ultra Fine Eutectic Structure Using Rapid Quenching Method and Plasma Sintering Technique; Final rept. 25 Jan 2007-23 May 2008

摘要

It is well known that cooling a melt of eutectic composition forms a characteristic structure. In this structure two phases entangles each other, which is called eutectic structure. Such structure is due to an alternate switching of crystallizing components from the melt. The size is generally small 'below micrometer'. The structure is self-forming composite, which can be used for many composite materials. Kakegawa et al. emphasized the effect of diffusion in liquid phase during the formation of eutectic structure. Diffusion and convection of liquid phase delay the switching rate of crystallizing components. Based on this idea, Kakegawa et al. used amorphous phase as a mother phase instead of the melt in GaAlO3-Al2O3 and YAG-Al2O3 system and succeeded to make ultra fine eutectic structures. Eutectic structures having a size of several ten nanometers, which is much smaller than that by the ordinary method, could be obtained by this process.