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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。
The gravity casting of ceramic shell of Ti Al Nb alloy melted by induction shell was studied. The microstructure and porosity of the cast alloy were analyzed by SEM, EDX and XPS. It is found that the oxide film exists in the pores and shrinkage cavities and is an inhomogeneous nucleation site of these defects. On the one hand, these pores are entrained with gases during casting and accumulate with small molecules of gas. These pores are widespread in the surface and center of the castings. Casting diameter, mold temperature, and argon partial pressure have a certain impact on the formation of stomatal defects.