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介绍了砂型铸钢用烧结剥离型防气孔和防增碳涂料、新型浅色烧结剥离型铸铁涂料、粘土湿型砂铸造醇基喷涂涂料、代替锆英粉涂料生产中大型碳钢和合金钢铸件的铬铁矿粉涂料、防止铸件脉纹缺陷的激冷涂料和绝热涂料、高压无气喷涂机等的性能特点及应用实例,简要探讨了国内砂型铸造涂料领域的发展方向. 相似文献
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采用甲苯磺酸作催化剂的呋喃树脂自硬砂生产稀土镁球铁件,通常会在铸件表层出现片状石墨异常组织,显著降低冲击值.研究发现,使用碳酸钙、赤泥、还原性钢渣等碱性无机化合物涂料和采用含有长石粉、滑石粉的烧结型涂料时,能吸收和阻止对甲苯磺酸受热分解析出的含硫气体侵入铸件表层,有助于消除球铁件界面硫的富集,防止铸件表面形成异常组织. 相似文献
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防渗碳涂料在低温时固相烧结的收缩性 ,阻渗材料的转化温度 ,在工艺温度下涂层的致密性 ,以及涂层组分的化学稳定性、粘度和表面张力是该涂料是否防渗的关键。目前国内热处理行业所使用的防渗涂料多采用生料配制而成[1,2 ] ,这些防渗涂料不同程度地存在上述几方面的问题 ,因而在使用中常常出现漏渗。本文作者研制出一种硅酸盐型的防渗材料 ,其中用熔块釉 (熟料 )作阻渗材料 ,已成功应用于生产实践。1 试验材料及方法 本防渗碳涂料有以下部分组成 :(1 )阻渗材料 :亦称熔质料 ,它是保护涂层的主要组成部分。本试验选用了一种固液相转化温… 相似文献
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易剥离粘砂层理论在铸铜涂料中的实践 总被引:1,自引:0,他引:1
大型推进器铸件铸型涂料是为实现烧结剥离型涂料系列化和引进技术国产化而研制的新型涂料,具有较高的理论和实用意义。本涂料使用与金属氧化物(氧化铜、氧化锡等)不起反应的碱性耐火材料作基材,有助于氧化物隔离层的沉积,具有良好的剥离性;调节硅铝酸盐的组成使它迫近最低共熔点,并添加适宜的助熔剂;本涂料使用无机膨润土代替有机膨润土作醇基涂料的稠化剂,具有悬浮性好,不用苯作活化剂,点燃黑烟少等优良性质。浇注后,烧结的涂层能自动从铸件上剥离下来,铸造缺陷少,清理方便。 相似文献
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大型铜合金铸件铸型涂料是为实现烧结剥离型铸型涂料系列化和引进技术国产化而研制的新型涂料,具有较高的理论和实用意义。本涂料使用与金属氧化物(氧化铜、氧化锡等)不起反应的碱性耐火材料作基材,有助于氧化物隔离层的沉积,具有良好的剥离性;调节硅铝酸盐的组成,使它迫近最低共熔物,并添加适宜的助熔剂;本涂料使用无机膨润土代替有机膨润土作醇基涂料的稠化剂,具有悬浊性好,不用苯作活化剂,点燃黑烟少等优良性质。浇注后,烧结的涂层能自动从铸件上剥落下来,铸造缺陷少,清理方便。 相似文献
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Molds made of gray cast iron for casting pig iron ingots are subjected to severe temperature fluctuations. The main life-
limiting factor for mold damage is the formation of surface cracks arising from thermal fa-tigue. Various flame and plasma
sprayed coatings were investigated to extend the life of these molds. Coating materials studied include plasma sprayed ceramic
coatings with bond coats as well as flame sprayed oxidation- resistant alloy powders. The results of cyclic furnace tests
from room temperature to 1100 °C in air, simulating the thermal cycle in casting, indicated that failure occurred along the
interface between the bond coat and the gray iron substrate because of iron oxidation, and not at the interface between the
ceramic top coat-ing and the bond coating for a superalloy substrate. The field test results indicated that plasma sprayed
alumina coatings with 200 μm top coating thickness are the most promising materials for pig iron casting. 相似文献
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原位反应法制备的碳化硅涂层/三维编织碳纤维的氧化性能研究 总被引:3,自引:0,他引:3
采用原位反应法在三维编织碳纤维(原纤维)表面制得β-SiC涂层,通过XRD,SEM,等温氧化失重和非等温热重分析等测试手段研究了制备方法对涂层性能的影响.结果表明:利用此法可得到均匀、完整,界面结合良好的涂层,涂层厚度增加,涂层/三维编织碳纤维(复合纤维)抗氧化性能增强.并对复合纤维氧化反应的机理进行了研究. 相似文献
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Eduardo K. Tentardini Augusto O. Kunrath Cesar Aguzzoli Maria Castro John J. Moore Israel J.R. Baumvol 《Surface & coatings technology》2008,202(16):3764-3771
The stability against reaction with aluminum of materials and coatings commonly used in aluminum die casting was investigated. The materials considered here were H13 tool steel and Anviloy® 1150, whereas the coatings were TiN and CrN. Special model, freestanding, multilayered thin film structures were used in this study, in association with complementary differential scanning calorimetry and X-ray diffraction. The nature of the reactions (endo or exothermic) and their onset temperatures up to 1273 K were determined. Based on of these results, some activation energies for the different reactions taking place between aluminum and die material or between aluminum and coatings could be established. Different intermetallic compounds were formed in these reactions, which were identified by post mortem X-ray diffraction analysis. Anviloy® 1150 showed superior stability as compared to H13 tool steel, whereas CrN was more inert than TiN coatings. CrN exhibited the best performance among all materials and coatings considered here, although its practical application relies also on adhesion of the CrN coating to the die bulk material. The results are discussed on the lights of two recent models for soldering in aluminum die casting. 相似文献
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针对V法铸造工艺的特殊性,分析了V法铸造涂料快干性、粘附性、致密性、透气性和涂挂性的影响因素,介绍了涂料性能的测试方法.将研制的V法铸造涂料用于高锰钢铸件,试用结果表明,涂料具有较快的干燥速度、与薄膜较好的粘附性、合理的透气性和致密性及良好的涂挂性,可满足V法铸造耐磨铸件的工艺要求,有效提高耐磨铸件的质量. 相似文献
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U.C. Nwaogu T. PoulsenR.K. Stage C. BischoffN.S. Tiedje 《Surface & coatings technology》2011,205(16):4035-4044
Foundry refractory coatings protect bonded sand cores and moulds from producing defective castings during the casting process by providing a barrier between the core and the liquid metal. In this study, new sol-gel refractory coating on phenolic urethane cold box (PUCB) core was examined. The coating density, viscosity, moisture content and wet and dry weight of the coating were evaluated on cores that had been coated at three different dip-coating times. The coating coverage, surface appearance and depth of penetration into the cores were examined with a Stereomicroscope. Gray iron castings were produced with sol-gel coated and uncoated cores and the results were related to the coating properties. The casting results were also compared with castings made with cores coated with commercial alcohol-based and water-based foundry coatings. The analyses show that castings produced with sol-gel coated cores have better surface quality than those from uncoated cores and comparable surface quality with the commercial coatings. Therefore, the new sol-gel coating has a potential application in the foundry industry for improving the surface finish of castings thereby reducing the cost of fettling in the foundry industry since the raw materials and technology are easily affordable. 相似文献
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