Eutectic nucleation in Al-7 wt pct Si-Mg casting alloys

被引:0
作者
Chen, Zhongwei [1 ]
Ma, Cuiying [1 ]
Zhao, Jing [1 ]
机构
[1] Northwestern Polytech Univ, State Key Lab Solidificat Proc, Xian 710072, Peoples R China
关键词
Al-Si-Mg alloy; Eutectic nucleation; Ce and Sr addition; DSC; SOLIDIFICATION; STRONTIUM; MICROSTRUCTURE; BETA-AL5FESI; PHOSPHORUS; MECHANISM;
D O I
10.11890/1006-7191-125-340
中图分类号
TF [冶金工业];
学科分类号
0806 ;
摘要
The nucleation of eutectic crystals of hypoeutectic Al-7 wt pct Si-Mg casting alloys modified by Ce and Sr was studied by using differential scanning calorimeter (DSC) and scanning electron microscope (SEM). DSC results were applied to calculate the values of activity energy and nucleation work of eutectic nucleation for the alloys. These values were decreased and the eutectic nucleation frequency was increased with the addition of Ce and Sr to the alloys. Moreover, the morphology of eutectic silicon in the modified alloys was partially or fully modified as fine, fibrous or coral, and DSC plots show that the eutectic undercooling of Al-7 wt pct Si-Mg alloys were increased with additions of modified agents. The mechanism of eutectic modification is combined actions of the accelerated nucleation and the restricted growth.
引用
收藏
页码:340 / 346
页数:7
相关论文
共 23 条
[11]   HETEROGENEOUS NUCLEATION OF SOLIDIFICATION OF SI IN AL-SI AND AL-SI-P ALLOYS [J].
HO, CR ;
CANTOR, B .
ACTA METALLURGICA ET MATERIALIA, 1995, 43 (08) :3231-3246
[12]   Microstructure selections in the undercooled hypereutectic Al-Si alloys [J].
Kang, HS ;
Yoon, WY ;
Kim, KH ;
Kim, MH ;
Yoon, YP .
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, 2005, 404 (1-2) :117-123
[13]   REACTION KINETICS IN DIFFERENTIAL THERMAL ANALYSIS [J].
KISSINGER, HE .
ANALYTICAL CHEMISTRY, 1957, 29 (11) :1702-1706
[14]  
Knuutinen A., 2001, Journal Light Metals, V1, P229, DOI [10.1016/S1471-5317(02)00004-4, DOI 10.1016/S1471-5317(02)00004-4]
[15]   Eutectic Solidification in Near-eutectic Al-Si Casting Alloys [J].
Liao, H. C. ;
Zhang, M. ;
Bi, J. J. ;
Ding, K. ;
Xi, X. ;
Wu, S. Q. .
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY, 2010, 26 (12) :1089-1097
[16]   Modification of AlSi alloys with sodium [J].
Qiyang, Liu, 1991, (39) :2497-2502
[17]   THE MECHANISM OF SILICON MODIFICATION IN ALUMINUM-SILICON ALLOYS - IMPURITY INDUCED TWINNING [J].
LU, SZ ;
HELLAWELL, A .
METALLURGICAL TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE, 1987, 18 (10) :1721-1733
[18]   Eutectic nucleation in Al-Si alloys [J].
McDonald, SD ;
Nogita, K ;
Dahle, AK .
ACTA MATERIALIA, 2004, 52 (14) :4273-4280
[19]   Aluminium phosphide as a eutectic grain nucleus in hypoeutectic Al-Si alloys [J].
Nogita, K ;
McDonald, SD ;
Tsujimoto, K ;
Yasuda, K ;
Dahle, AK .
JOURNAL OF ELECTRON MICROSCOPY, 2004, 53 (04) :361-369
[20]   Effects of boron on eutectic modification of hypoeutectic Al-Si alloys [J].
Nogita, K ;
Dahle, AK .
SCRIPTA MATERIALIA, 2003, 48 (03) :307-313