急速凝固によるAl-Si合金の組織超微細化について

抄録

Eutectic and hypereutectic Al-Si alloys were rapidly solidified at solidification rates of the order of 10³°C/sec and more, and their microstructures and mechanical properties were investigated. By the rapid solidification, extremely fine eutectic structures with an average silicon size of 0.1μ were produced, and the solid solubility of Si in Al was much increased. For hypereutectics, a uniformly refined eutectic structure without primary silicon was produced up to 17 wt%Si by the rapid solidification. Mechanical properties of the Al-Si alloys were considerably improved, especially in hardness by the “quench-modification”, the maximum values of which were obtained by the precipitation of silicon particles from the supersaturated solution when aged at 130°∼150°C for 2 hrs.