Radkovský Filip, Gawronová Martina, Merta Václav, Lichý Petr, Kroupová Ivana, Nguyenová Isabel, Kielar Šimon, Folta Martin, Bradáč Josef, Kocich Radim
Department of Metallurgical Technologies, Faculty of Materials Science and Technology, VSB-Technical University of Ostrava, 17. Listopadu 2172/15, 708 00 Ostrava, Czech Republic.
Brembo Czech, s.r.o. Na Rovince 875, 720 00 Ostrava, Czech Republic.
Materials (Basel). 2022 Sep 5;15(17):6180. doi: 10.3390/ma15176180.
In the foundry industry, silica sands are the most commonly used type of sands for the production of sand foundry moulds using various types of binders. Their greatest disadvantage is their significant volume changes at elevated temperatures, which are associated with the formation of many foundry defects from stress, such as veining, and thus have a direct influence on the final quality of the casting. In the case of non-silica sands and synthetic sands, the volume stability is more pronounced, but this is accompanied by a higher purchase price. Therefore, a combination of silica sand and synthetic sand CERABEADS is considered in order to influence and reduce the thermal expansion. The hybrid mixtures of sands, and their most suitable ratios, were evaluated in detail using sieve analysis, log W and cumulative curve of granularity. It was found that the addition of 50% CERABEADS achieves a 32.2% reduction in dilatation but may increase the risk of higher stresses. The measurements showed a significant effect of the granulometric composition of the sand on the resulting thermal expansion, where the choice of grain size and sorting can achieve a significant reduction in dilatation with a small addition of CERABEADS.
在铸造行业中，硅砂是使用各种粘结剂生产砂型铸造模具时最常用的砂型。它们最大的缺点是在高温下会发生显著的体积变化，这与许多因应力产生的铸造缺陷有关，如脉纹，从而直接影响铸件的最终质量。对于非硅砂和合成砂，体积稳定性更为明显，但这伴随着较高的采购价格。因此，考虑将硅砂和合成砂CERABEADS结合使用，以影响和减少热膨胀。使用筛分分析、log W和粒度累积曲线详细评估了砂的混合混合物及其最合适的比例。结果发现，添加50%的CERABEADS可使膨胀率降低32.2%，但可能会增加产生更高应力的风险。测量结果表明，砂的粒度组成对热膨胀有显著影响，通过选择粒度和分选，只需少量添加CERABEADS就能显著降低膨胀率。
