Modifying agent selection for Al-7Si alloy by Miedema model

作     者：Zhong-wei Chen Cui-ying Ma Pei Chen 

作者机构：State Key Laboratory of Solidification ProcessingNorthwestern Polytechnical UniversityXi'an 710072China 

出 版 物：《International Journal of Minerals,Metallurgy and Materials》 (矿物冶金与材料学报（英文版）)

年 卷 期：2012年第19卷第2期

页      面：131-135页

核心收录：

学科分类：08[工学] 080502[工学-材料学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0835[工学-软件工程] 081202[工学-计算机软件与理论] 0812[工学-计算机科学与技术（可授工学、理学学位）] 

基　　金：supported by the Research Fund of the State Key Laboratory of Solidification Processing (No.42-QP-009) the Open Fund of the State Key Laboratory of Solidification Processing in NWPU (No.201009) the Fundamental Research Fund of Northwestern Polytechnical University (No.JC200929) the 111 Project of China (No.B08040) 

主　　题：aluminum alloys silicon alloys modifying agents rare earth elements microstructure enthalpy 

摘      要：To determine the modifying agents for Al-7Si alloys, microstructure observation and mixing enthalpy analysis using Miedema model for Al-7Si alloy with additions of different rare earth elements were performed, and the effects of rare earth elements on the modifica-tion of eutectic silicon morphology were investigated. The results of mixing enthalpy analysis show that these four rare earth elements, La, Sm, Pr, and Ce, which have the large negative mixing enthalpies with Si, can be selected as modifying agents for eutectic silicon morphology. The element with the largest negative mixing enthalpy is Ce. Furthermore, the microstructures indicate that these four elements can effec-tively modify the eutectic （α）Al-Si crystals in Al-7Si alloy, and the most effective one is also Ce. Differential scanning calorimetry （DSC） results show that the eutectic temperature depressions due to the additions of modifying agents are the important reasons for the modification of eutectic （α）Al-Si crystals.