The Effect of Mg Adding Order on the Liquid Structure and Solidified Microstructure of the Al-Si-Mg-P Alloy: An Experiment and ab Initio Study

Metals

Xiangzhen Zhu²  Wei Jiang²  Mingrui Li²  Huan Qiao²  Yuying Wu²  Jingyu Qin¹  Xiangfa Liu¹ 

[1] Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, Shandong University, 17923 Jingshi Road, Jinan 250061, China;

关键词: AlP;    Mg;    modification;    Al-Si alloy;    liquid structure;    evolution;    simulation;   

DOI  :  10.3390/met5010040

来源: mdpi

【 摘 要 】

In this paper, the relationship between the liquid structure and the corresponding solidified microstructure of an Al-Si-Mg-P alloy was studied. Experimental results show that Mg can reduce the phosphorous-modification effect if it was added after adding Al-P alloy. However, when it is added before adding Al-P alloy, Mg has no effect on the phosphorous-modification. It is considered that the difference in liquid structure induced by changing the adding order of Mg should be responsible for the above phenomenon, and was investigated by ab initio molecular dynamics simulation (AIMD). It was believed that the high-active Mg atoms could bond P atoms to form P-Mg clusters and then reduce the modification effect of AlP, when pure Mg was added into the prepared Al-Si-P melt. When the pure Mg was added into Al-Si melt before adding Al-P alloy, the Mg atoms would be first occupied by Si atoms to form Mg-Si clusters, and thus lose the ability to eliminate P-Al clusters which dissolve into melt later, leading to a good phosphorous-modification effect.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.