Fig. 4. Seen from the cast side, the casting defect takes the form of a white film with black inclusions.


图4. 铸件侧视图，铸件 缺陷表现为带有黑色夹 渣的白膜。


the close-up image (Fig. 5a), spectrum 1 shows a sand grain with the carbon and iron inclusions. In addition, a sand grain with sulfur and carbon components from the analyses can be seen (spectrum 3). On further magnifica- tion of the image (Fig. 5b), the carbon inclusions that most likely originate from the binder bridges (spectrum 1) can be seen. Tis supposition is confirmed by the sulfur and carbon components, which can be seen in spectrum 1. It can be confirmed on this basis that the carbon and sulfur originate from the binder system for the mold material resin and caused the casting defect. Te images also show the coating areas (spectrum 3) and fibrous silicon (spec- trum 2). On further magnification of the casting defect (Figs. 6a


and b), the compact white and black, coral-shaped phases can be seen. Te compact white mass consists of pure silicon and oxygen. Te coral-shaped phase mainly consists of carbon.


谱3）。在进一步放大的图像（图5b）中，可以看到很 可能由中间粘接剂（光谱1）产生的碳夹渣。可以从光 谱1中看到的硫和碳成分证实了这一假设。由此，可以 确认碳和硫来源于造型材料树脂的粘接剂体系，并导致 了铸件缺陷。该图还显示了涂层区域（光谱3）和纤维 状硅（光谱2）。


进一步放大铸件缺陷（图6a和6b）后，可以看到压 紧的黑白色珊瑚状的现象。压紧的白色物质由纯硅和氧 组成。珊瑚状现象主要由碳组成。


除详细的SEM分析外，还对铸件缺陷进行了X射线衍 射分析（XRD）。该过程证实了样品由非晶SiO2 碳组成。


和胶体 详细的铸件缺陷分析表明，白膜由三种相组成：硅、


Fig. 5. SEM images of the mold material side depict the vari- ous spectrums of the defect.


图5. 造型材料侧 的SEM图显示了 缺陷的各种光谱。


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