電析非晶質Crおよび非晶質Cr-Mo合金の結晶化過程

抄録

This report describes the crystallization processes of the amorphous Cr and the amorphous Cr-Mo binary alloys which were prepared by the electoroplating method. The crystallization processes of the amorphous Cr and the amorphous Cr-Mo binary alloys were investigated by differential thermal analysis (DTA) and transmission electron microscope (TEM). The crystallization onset temperature of the amorphous Cr, Cr-2.3at%Mo, and Cr-5.2at%Mo alloys were 773K, 838K, and 878K, respectively. The rise of crystallization onset temperature by the addition of Mo indicated that the molybdenum contributed to the thermal stability of the amorphous Cr. The cubic crystals of about 30nm diameter, which were the b.c.c. chromium single crystals consisting of six {001} planes, precipitated in the initial crystallization stage of the amorphous Cr. In the perfectly crystallized chromium film, numerous micro twins were observed in the original amorphous region which the cubic crystals did not precipitate. The crystallization process of the Cr-2.3at%Mo alloy was similar to that of the amorphous Cr except for the next two phenomena. The one phenomenon was that the size of precipitated cubic crystals was about 80nm diameter, and the other was that density of micro twins was more than that of the amorphous Cr. It was found from the measurement of lattice constants that the crystals precipitated in Cr-Mo alloys were stable solid solutions.