水玻璃砂微波硬化特性及溃散性的研究

【作者】 李艳芬；

【导师】 刘向东；

【作者基本信息】 内蒙古工业大学 ， 材料加工工程， 2005， 硕士

【摘要】 水玻璃砂具有价格低、强度高、无毒等优点,在铸造生产中获得广泛应用,但是由于其溃散性差,因此不能完全取代其它粘结剂。改善水玻璃砂溃散性的措施有多种,但均不能达到令人满意的效果。解决水玻璃砂溃散性的根本途径是提高水玻璃的粘结效率,减少其加入量。本文采用微波加热来硬化水玻璃砂,充分利用微波加热的特点,使砂粒表面的水玻璃膜在加热过程中同时发生硬化反应,从而提高水玻璃粘结效率,达到改善溃散性的目的。研究了在不同加热功率和加热时间的条件下,水玻璃加入量、模数、改性剂等对水玻璃砂性能的影响。结果表明:未改性水玻璃砂强度在硬化10 分钟时达到最大值;硬化工艺参数相同时,水玻璃模数越低,水玻璃砂强度值越高;水玻璃加入量相同时,4#改性水玻璃砂强度明显高于未改性水玻璃砂强度;在满足常温强度性能要求的前提条件下,4#改性水玻璃砂残留强度比未改性水玻璃砂残留强度低0.47～0.6MPa,溃散性明显得到改善。如果生产中使用该改性水玻璃,水玻璃加入量能降到1.5%及以下。更多还原

【Abstract】 The sodium silicate sands were widely used in the commercial foundry for its notoxicity, high strength and low price. But the other adhesives in molding sands have not beenstill entirely replaced with the sodium silicate for its bad collapsibility. There are a lot ofmethods to improve the collapsibility, but their effects are not pleasing.An essential approach to solving the problem of low collapsibility is enhancing bondingefficiency of sodium silicate and reducing sodium silicate amount. Because the sodiumsilicate films covered sands heating by microwave can be cured at the same time, themicrowave-heating process was used in the present work. The bonding efficiency of thesodium silicate was obtained and the collapsibility was developed.The influences of the modulus of sodium silicate and the amount of modifying agentadded on the properties of sodium silicate sands with the different time and power ofmicrowave heating were investigated in this work. The results indicate that the tensilestrength of the unmodified sodium silicate sands reach the maximum value as heating for tenminutes. In the same parameter of hardening process, the lower modulus of sodium silicateis, the higher its tensile strength. With the same amount of sodium silicate, the tensilestrength of 4# modified sodium silicate sands is obviously higher than that of the unmodified.The retained strength of 4# modified sodium silicate sands is lower 0.47~0.6MPa than that ofthe unmodified so that the obvious low retained strength , i. e. a good collapsibility wasobtained. The amount of sodium silicate in the sands may reduce to 1.5 percent even lesswith the modified sodium silicate in foundry practice.更多还原