Morphology and microstructure of rapidly solidified tin-lead alloy powders  

作　　者：Xiang Qingchun Zhang Wei Qiu Keqiang Qu Yingdong Li Rongde 

机构地区：[1]School of Materials Science and Engineering, Shenyang University of Technology

出　　处：《China Foundry》2014年第5期428-434,共7页中国铸造（英文版）

基　　金：supported by the Natural Science Foundation of Liaoning Province (No.20072043)

摘　　要：Sn60Pb40 al oy powders were fabricated using the planar flow casting （PFC） atomization process. By using OM, SEM and EPMA, the characteristics of the morphologies and microstructures of the powders have been investigated. It is observed that the environment of ambient gas in the atomization box has great effects on the morphology of the al oy powders. The microstructures of Sn60Pb40 al oy powders produced by the PFC atomization process are completely composed of eutectic, which is made up of both oversaturated αsolid solution and β solid solution. The microstructures of smal size powders are extraordinarily undeveloped dendritic eutectic, in which the large majority of the α phase appears nearly spherical, evidently since the cooling rate is higher and the under-cooling is larger. As for the large size powders, since the cooling rate and undercooling are relatively low, lamel ar α phase apparently increases in the eutectic microstructures of these powders, and there is even typical lamellar eutectic structure clearly observed in some micro-areas. After remelting tests by DTA, the microstructures of smal size powders are transformed, which become composed of large crumby α phase and eutectic （α＋β）, while those of large size powders change into classical tin-lead structures of primary α phase plus lamellar eutectic （α＋β）. By studying the microstructures of tin-lead alloy powders, a model has been proposed to predict the microstructure formation of Sn60Pb40 al oy powders.Sn60Pb40 alloy powders were fabricated using the planar flow casting(PFC) atomization process. By using OM, SEM and EPMA, the characteristics of the morphologies and microstructures of the powders have been investigated. It is observed that the environment of ambient gas in the atomization box has great effects on the morphology of the alloy powders. The microstructures of Sn60Pb40 alloy powders produced by the PFC atomization process are completely composed of eutectic, which is made up of both oversaturated α solid solution and β solid solution. The microstructures of small size powders are extraordinarily undeveloped dendritic eutectic, in which the large majority of the α phase appears nearly spherical, evidently since the cooling rate is higher and the under-cooling is larger. As for the large size powders, since the cooling rate and undercooling are relatively low, lamellar α phase apparently increases in the eutectic microstructures of these powders, and there is even typical lamellar eutectic structure clearly observed in some micro-areas. After remelting tests by DTA, the microstructures of small size powders are transformed, which become composed of large crumby α phase and eutectic(α+β), while those of large size powders change into classical tin-lead structures of primary α phase plus lamellar eutectic(α+β). By studying the microstructures of tin-lead alloy powders, a model has been proposed to predict the microstructure formation of Sn60Pb40 alloy powders.

关 键 词：rapid solidification planar flow casting tin-lead alloy metal powders MICROSTRUCTURE 

分 类 号：TG146.14[一般工业技术—材料科学与工程]