Microstructures of electromagnetic casting and direct chill casting LY12 aluminum alloys

来源期刊：中国有色金属学报(英文版)2003年第2期

论文作者：曹志强 金俊泽 郝海 贾非

文章页码：348 - 352

Key words：electromagnetic casting; continuous casting; aluminum alloy; microstructure; hardness

Abstract: LY12 aluminum alloys made by electromagnetic casting (EMC) and direct chill casting (DCC), were analyzed by optical microscope, differential scanning calorimetry, transmission electron microscope and X-ray diffraction. It is found that the surface and subsurface quality of the ingot is improved largely due to the absence of an ingot mold, which is impossible to achieve with conventional DCC. It is also found that the intense forced convection can promote the fast superheat evacuation and break the dendrite arms, leading to the grain multiplication and the appearance of a fine equiaxed grains over the whole cross section. As a result, the hardness of EMC specimens increases one time than that from DCC in the as-cast state. Even though after the solid solution treatment and the artificial aging, the DCC ingot still can not get the same hardness as EMC ones.