When precision casting surface layer coating powder was relatively low, the surface layer of the shell hole more, most likely to form burr. This mechanism can be used to select wet paint to analyze: the wetting angle of paint modules with large and easy to spread, but the refractory powder, but it can be well wetting and spreading.
When the liquid surface of the layer of powder coating material is relatively low, less cohesive coating, the coating thickness of the surface layer is thin. When the withdrawal of sand, sand easily penetrate the coating. Several sand thus formed between a small puddle. Inside the pool filled with paint, since there is a narrow sand between the gap, under capillary action, paint is attracted to the gap at the sand, coated sand, which hardened after coating, close on the module side precision casting surface to form A small holes, these holes or dense single existence, though the shape of the rules, but the basic round or flat round. After pouring the molten metal, liquid metal into the pores of the formation of a burr defects.
For burr, way before we can be cured air-dried not less than 30 minutes, so you can take off part of the free water, slowing the contraction during hardening gel, silica sol has good continuity and compactness, can greatly reduce the hole defects, reduce the casting burr, defect generation. In addition, the refractory powder particle size distribution of the dispersion, the greater mosaic density. You can configure a both a high powder-liquid ratio, but also has good process performance coatings, in order to prevent glitches phenomenon precision castings. |
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Wuxi Yongsheng Metals Goods Co.,Ltd.
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Contact: Zhiyong Lu
Contact: Miss Ma
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