间接超声振动制备5052铝合金半固态浆料

来源期刊：金属学报2011年第5期

论文作者：吕书林 吴树森 戴维 安萍 毛有武

文章页码：634 - 640

关键词：间接超声振动； 初生晶粒； 空化效应； 半固态浆料

Key words：indirect ultrasonic vibration； primary grains； cavitation effect； semi-solid slurry

摘    要：采用一种新型的间接超声振动装置制备5052铝合金半同态浆料,研究了启振温度和振动时间对浆料组织的影响.结果表明,在液相线温度643℃及以上开始对5052铝合金熔体进行50 s的间接超声处理,能获得晶粒细小圆整的半固态浆料.在液相线温度开始通过杯底对合金熔体进行间接超声处理,可在杯底附近大量形核,随后初生晶粒以球状方式生长;在60 s的制浆时间内,晶粒平均直径先减小后增大,平均形状系数则一直增大.熔体温度降至液相线以下3℃时再进行间接超声处理,亦能破碎发达的枝晶获得蔷薇状组织和球状晶粒共存的半固态浆料,晶粒平均直径为105μm.

Abstract: A new indirect ultrasonic vibration (IUV) apparatus was employed to prepare semisolid 5052 aluminum slurry.The effects of IUV temperature and time on the morphology of the semisolid slurry were studied.The results indicate that semisolid slurry with fine and globular primary grains can be obtained by applying IUV from the liquidus temperature (643℃) of this alloy or a higher temperature for about 50 s.When IUV is applied through the bottom of the metal cup at 643℃,a lot of nuclei form near the bottom of metal cup and these nuclei grow into globular grains.In this stage,the average diameter of primary grains decreases as IUV time increased up to 30 s and then it increases with further increasing of IUV time from 30 s to 60 s.and the average shape coefficient of primary grains increases as IUV time increased.When the IUV is applied at 640℃,dendrites can be broke up and a mixture structure consisted of rosette and globular grains with a average diameter of 105 μm is obtained.