铸造条件对重力铸造TiAlNb铸件缩孔及夹杂气泡的影响（英文）  

Effect of Casting Conditions on Layer Porosity and Entrained Bubbles in Gravity-filled TiAlNb Castings

作　　者：宫子琪[1] 柴丽华[1] 周峰[1] 陈子勇[1] 聂祚仁[1] 

机构地区：[1]北京工业大学,北京100124

出　　处：《稀有金属材料与工程》2016年第10期2485-2491,共7页Rare Metal Materials and Engineering

基　　金：EU and ESA through the IMPRESS Integrated Project-Intermetallic Materials Processing in Relation to Earth and Space Solidification(NMP3-CT-2004-500635);National Natural Science Foundation of China(51301005)

摘　　要：研究了感应凝壳炉熔炼的Ti Al Nb合金的陶瓷型壳重力浇铸。使用了扫描电镜(SEM),能谱仪(EDX)以及X射线光电子能谱(XPS)对铸造合金的显微组织及气孔缺陷进行分析。研究发现,氧化膜在气孔及缩孔中存在并且是这些缺陷的不均匀形核位置,而这些气孔缺陷一方面是浇铸过程中气体夹带形成,另一方面是气体小分子积聚形成。这些气孔广泛存在于铸件的表层及中心部分。铸件直径,模具温度,以及氩分压都对气孔缺陷的形成有一定的影响。Gravity-pouring of a TiAlNb alloy from an induction skull melting （ISM） furnace into a ceramic shell mould has been carried out in this paper. Microstructure and gas defects were examined by employing scanning electron microscopy （SEM）, energy-dispersive X-ray （EDX） and X-ray photoelectron spectroscopy （XPS） analysis. It has been found that oxide films existed in the form of bubbles and porosity, and acted as defects’ heterogeneous nucleation sites. The bubbles consisted of entrained and precipitable ones, while the porosity consisted of layer and centerline ones. The diameter of casting bars, mould temperature and the partial pressure of argon had an effect on the formation of gas defects.

关 键 词：钛铝基合金 铸造 微观组织 缺陷 

分 类 号：TG292[金属学及工艺—铸造]