Surface formation in direct chill (DC) casting of 6082 aluminium alloys

4th International Conference on Advances in Solidification Processes

材料科学;物理学

Bayat, N.^1 ; Carlberg, T.^1

Department of Natural Science, Mid Sweden University, Sundsvall

851 70, Sweden^1

关键词: 6082 Aluminium alloys;    Direct chill casting;    Exudation of liquids;    Segregation patterns;    Solidification directions;    Surface appearance;    Surface formation;    Surface microstructures;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/117/1/012038/pdf
DOI  :  10.1088/1757-899X/117/1/012038

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

Surface defects in aluminium billet production are a real problem for the subsequent extrusion procedure. Extrusion productivity can be influenced by the surface properties, which is defined as surface appearance, surface segregation zone depth and large Mg2Si and β-particles (Al5FeSi). In this research the surface formation during DC casting of 6082 aluminium billets produced by the air slip technology is studied. The surface microstructures of 6082 aluminium alloys with smooth and wavy surface appearances were investigated, including segregation zone depths and phase formation. The results were discussed based on the exudation of liquid metal through the mushy zone. The specific appearance of the wavy surface of 6082 alloys was correlated to how the oxide skin adheres to the underlying mushy zone and coupled to the dendritic coherency and surface tension of the skin. The occurrence of different phases at the very surface and in the layer just below was explained by variations in solidification directions and subsequent segregation patterns.