用铜模快冷法制备均质Al-In过偏晶合金

PREPARATION OF HOMOGENEOUS Al-In HYPER- MONOTECTIC ALLOYS WITH COPPER MOULD RAPID SOLIDIFICATION METHOD

采用铜模快冷工艺制备了均质的Ａｌ－Ｉｎ过偏晶合金，分析了合金熔配过程、合金成分以及冷却速率对显微组织的影响．研究结果表明，对于质量分数不大于 ３０％Ｉｎ的合金成分，１１７３ Ｋ时保温 ４０ ｍｉｎ 以上时可得到均匀的单一合金熔体．采用铜模快冷方法可以得到第二相颗粒均匀分布的至少 ４ ｍｍ厚的均质合金薄板．Ｉｎ颗粒尺寸分布具有双峰分布形式．随着 Ｉｎ含量的增加或薄板厚度的增大即冷却速率的降低，Ｉｎ颗粒的平均尺寸增大．

Homogeneous Al-In hypermonotectic alloys have been fabricated by copper mould rapid solidification technique and the effects of the melting process, the composition and the cooling rate on the microstructure have also been investigated. The results show that, for the alloys with mass fraction of indium less than 30%, the homogeneous alloy melt can not be obtained unless the holding time is not less than 40 min at 1173 K. The alloy sheets with at least 4 mm, in which the fine In particles disperse in the matrix, can be produced with the copper mould rapid solidification method. The size distribution of In particles within Al matrix is bimodal. Under the same cooling rate, the particles' average size increases with the rising contents of In. Under the same composition, the particles' average size decreases with increasing cooling rate.