作　　者： ; ; ; ; ;

机构地区： 华南理工大学机械与汽车工程学院

出　　处： 《金属学报》 2008年第8期905-910,共6页

摘　　要： 对低过热度浇注的半固态2024铝合金坯料分别以0.12,0.26和0.52℃/s的平均升温速率加热至625℃并保温;利用光学显微镜和金相图像分析系统研究了升温速率对坯料部分重熔组织的影响.结果表明,升温速率越快,坯料重熔越快,重熔后晶粒越细小和圆整.提高升温速率,有利于抑制晶间共晶相的溶解扩散和提高坯料的熔化过热温度,加快晶间液相形成,对晶粒合并长大具有一定的抑制作用,并加速品粒球化。 The semi solid 2024 alloy billets prepared by low superheat pouring method were reheated to 625℃ with heating rates of 0.12, 0.26 and 0.52 ℃/s, respectively, and then held isothermally. The effect of heating rate on the mierostructure of semi solid billets was studied by optical microscope and metallographic image analysis system. The results show that the higher the heating rate is, the quicker the remelting is and the finer and rounder the grains are. Increasing the heating rate is helpful to suppress the eutectic dissolution and rise the melting superheat temperature, which can accelerate the formation of liquid phase between grains, restrain the coalescence and growth of grains to a certain extent and accelerate the spheroidization.

关 键 词： 铝合金 半固态金属 部分重熔 升温速率 组织演变

领　　域： [金属学及工艺] [一般工业技术] [金属学及工艺]