喷涂表面强化剂对水玻璃砂表面安定性的影响

Effect of RSI Surface Coating on the Surface Stability of Sodium Silicate Bonded Sand

铸造用水玻璃砂为保证强度而需要在砂中加入较多的水玻璃,从而导致其溃散性差、表面严重粘砂以及旧砂回用困难等缺点。目前有研究通过向水玻璃砂中添加各种附加物在保证砂型强度的同时减少水玻璃的加入量。然而随着水玻璃砂中水玻璃加入量的减少,砂型表面安定性下降,砂型表面形状和完整性易被破坏。为提高砂型表面安定性,拟通过表面喷涂RSI表面强化剂的方式,于水玻璃砂样表面构筑一层强化层,以改善水玻璃砂样表面安定性。经研究发现,此强化层可将加入1.5%水玻璃的砂样的表面安定性从原有的61%提高至98%。分析认为:此强化层既能极大地提升试样表面的强度,又能通过填补砂粒间孔隙、改善试样的吸湿性。

For casting water glass sand,more water glass is added to the sand to ensure the strength,which leads to the disadvantages of poor collapsibility,sticky sand,and poor reusability of old sand.At present,there are studies by adding various reagents to the water glass sand to reduce the amount of water glass added while ensuring the strength of the sand mold.However,as the amount of water glass added to the water glass sand decreases,the surface stability of the sand mold decreases,and the shape and integrity of the sand mold surface are easily damaged.In order to improve the surface stability of the sand mold,the author intends to construct a layer of coating on the surface of the water glass sand sample by spraying the RSI reagent on the surface to improve the surface stability of the water glass sand sample.The study found that this coating can increase the surface stability of sand with 1.5%water glass from the original 61%to 98%.The analysis shows that the coating can greatly improve the strength of the surface of the sample as a binder,and improve the hygroscopicity of the sample by filling the pores between the sand particles.