型腔抽真空动力学与真空压铸技术评介  

Evaluation of Vacuuming Kinetics in Cavity and Vacuum Die Casting Technologies

作　　者：龙思远[1,2] 査吉利 干雪梅[1] 徐绍勇 曹韩学[1] 游国强[1] 

机构地区：[1]重庆大学材料科学与工程学院 [2]重庆硕龙科技有限公司

出　　处：《特种铸造及有色合金》2011年第11期981-985,共5页Special Casting & Nonferrous Alloys

基　　金：国家重点基础研究发展计划(973计划)资助项目(2007CB613702);重庆市科技攻关项目(CSTC2009AB4010;CSTC2010AA4045)

摘　　要：抽真空是消除铸件气孔缺陷的有效方法。在综述现有各种压铸真空系统抽真空动力学特点的基础上,指出现行压铸真空技术难以获得满意抽真空效果的原因是:为及时有效关断真空通道、阻止高速充型熔体进入真空系统而导致型腔抽真空速度过低。然后根据型腔气体排溢动力学理论,提出在确保真空通道及时关断的前提下,抽真空效果主要取决于抽真空系统的动态响应特征和型腔在高速熔体充填前所能达到的真空度;增大抽排气管路当量直径和减小管道长度是抽真空排气通道的设计关键,并展示了满足该原则的新型抽真空技术的使用效果。Vacuumming of die cavity is an effective way of producing quality castings free of defects associated with cavity gases.After an evaluation of the vacuuming behaviors of the vacuuming die casting technologies currently used in industry,it was pointed out that the dissatisfaction of current technologies steams from the commonly low vacuuming rate needed to effectively stop the melt flow from pennetrating into vacuuming system.In accordence with the vacuuming knetics of a die cavity,it is highlighted that an effective vacuuming relies on the kinetic response rate of the vacuuming system and the vacuum degree achieved before high speed die-filling in condition that the vacuuming channel could be effectively closed up.Enlarging the diameter and reducing the length of the vacuuming channel are the key criteria to a successful exhausting channel design.The application of a new type vacuuming system meeting the mentioned criteria was shown.

关 键 词：真空压铸 气体流动 气孔缺陷 排气通道 

分 类 号：TG249.2[金属学及工艺—铸造]