Effect of cooling rate and the original matrix on the thermal diffusion alloyed intermetallic layer on magnesium alloys. (15th April 2017)

• Record Type: Journal Article
• Authors: Lu, Dongzhu; Zhang, Qichao; Wang, Wencheng; Guan, Fang; Ma, Xiumin; Yang, Lihui; Wang, Xiutong; Huang, Yanliang; Hou, Baorong
• Is Part Of: Materials & design. Volume 120(2017)
• Page Start: 75
• Page End: 82
• Publication Date: 2017-04-15
• Subjects: Magnesium alloy -- Diffusion alloying -- Intermetallic layer -- Morphology -- Dendritic crystal -- Matrix; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2017.02.006
• Languages: English
• ISSNs: 0264-1275

Abstract

Abstract: In order to promote the utilization of the powder thermal diffusion alloying method to protect magnesium alloys, effect of cooling rate as well as the original state of the magnesium alloy specimens including chemical composition and thickness on the as diffusion alloyed intermetallic layer was investigated. The results show that water quenched specimens could have dendritic crystals in the intermetallic layer even at a diffusion temperature lower than the Mg-Al eutectic temperature. Thinner specimens and higher Al content are preferred for the powder thermal diffusion alloying process. Morphology of the Mg17 Al12 intermetallic layer with embedded α-Mg islands could be attributed to two main reasons, one is the decomposition of the unstable solution, and the other is liquid saturation and preferential diffusion at heterogeneous structures. Graphical abstract: Highlights: Dendritic crystals emerged in the intermetallic layer on water quenched as diffusion alloyed specimens. Thinner specimens and higher original Al content in matrix are preferred to the diffusion alloying process. Embedded α-Mg in the intermetallic layer is related to the decomposition of unbalanced solution. Liquid saturation and preferential diffusion at heterogeneous structures affect the morphology of the coating.