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本文从理论和实践两个方面探讨了大型、复杂铸件的失蜡铸造工艺,成功地将水玻璃砂芯用于失蜡铸造,这对复杂艺术品的精密铸造有意义, 相似文献
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微波硬化对水玻璃砂性能的影响 总被引:2,自引:0,他引:2
采用微波加热技术硬化水玻璃砂,系统测试并分析了水玻璃加入量、微波加热时间和加热功率对砂芯强度的影响规律。结果表明,在本实验条件下,水玻璃加入量和微波加热功率对砂芯峰值强度出现时间没有影响,峰值强度均出现在10min左右。加热时间超过20min以后,砂芯强度基本保持不变。 相似文献
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Bricks made of coal fly-ash and slag, cured in the open air 总被引:2,自引:0,他引:2
Volume mass, compressive strength, water uptake and water absorption of pressed test samples made of a mixture of coal fly-ash, slag and sodium silicate solution (water-glass) were determined. It was found that such mixtures can solidify in the open air and form water-stable materials. The composition and structure of new formations for the binder and cured material itself were established using X-ray diffraction and a scanning electron microscope. The material has a high water uptake, which may be reduced using a number of different methods, the best of which is short-term impregnation with a hydrophobic material of the siloxane group. The water uptake and water absorption of compressed samples impregnated with such materials are similar to those of comparable building materials, such as lime-sand bricks, clay bricks or concrete blocks. 相似文献
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水玻璃炉的PLC控制 总被引:1,自引:0,他引:1
利用可编程序控制器控制水玻璃炉自动换向。保证了水玻璃炉安全可靠地运行,同时降低了能耗。 相似文献
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甲苯二异氰酸酯和泡花碱交联聚乙烯醇类建筑胶水的研究 总被引:2,自引:0,他引:2
本文采用正交实验法,探讨在水基中甲苯二异氰酸酯(TDI)和泡花碱共同对聚乙烯醇(PVA)进行交联改性,形成一种新型环保建筑胶水。从反应原理和反应后体系中残存TDI游离的量来证明该建筑胶水的环保性。同时还探讨TDI和泡花碱的加入量、以及交联反应的温度等因素对该建筑胶水的180°剥离强度和耐水性能的影响。 相似文献
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《中国铸造》2016,(6):427-432
The paper presents the research results of using an innovative method to reclaim the waste moulding sands containing water glass. Two of the examined processes are connected with “dry” or “wet” activation of inorganic binder in waste moulding sand mixtures physicaly hardened by microwave radiation. The sand mixtures consisting of high-silica sand and water-glass with average molar module 2.5, were subjected to the folowing cyclical process: mixing the components, compacting, microwave heating, cooling-down, thermaly loading the mould to 800 °C, cooling-down to ambient temperature, and knocking-out. After being knocked-out, the waste moulding sands were subjected to either dry or wet activation of the binder. To activate thermaly treated inorganic binder, each of the examined processes employed the surface phenomenon usualy associated to mechanical reclamation. The study also covered possible use of some elements of wet reclamation to rehydrate waste binder. To evaluate the effectiveness of the two proposed methods of waste binder activation, selected strength and technological parameters were measured. After each subsequent processing cycle, the permeability, tensile strength and bending strength were determined. In addition, the surface of activated sand grains was examined with a scanning electron microscope. Analysis of the results indicates that it is possible to re-activate the used binder such as sodium silicate, and to stabilize the strength parameters in both activation processes. Permeability of the refreshed moulding sands strongly depends on the surface condition of high-silica grains. The wet activation process by wetting and buffering knocked-out moulding sands in closed humid environment makes it possible to reduce the content of refreshing additive in water-glass. The moulding sands cyclicaly prepared in both processes do not require the addition of fresh high-silica sand. The relatively high quality achieved in the refreshed moulding sands alows them to be reused for manufacture of next moulds. Thus, the two proposed methods for cyclicaly processing used moulding sands containing sodium silicate, subject to microwave hardening, are suitable for economic and ecological circulation moulding mixtures. 相似文献