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冷捣糊的特点和技术优势分析 总被引:1,自引:0,他引:1
冷捣糊问世30多年来,已在铝电解槽内衬上获得了广泛的应用.目前多数国家已禁用热捣糊,只能用冷捣糊或温捣糊(仅限夏天气温高于40℃时).环保、焙烧收缩率小、捣实性能好、强度适中以及便于机械化施工等优点是冷捣糊获得广泛应用的主要原因. 相似文献
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低捣固温度铝用冷捣糊的研究 总被引:5,自引:1,他引:4
研究低捣固温度或施工温度(8~25℃)铝用冷捣糊的理化指标达到挪威专家指导的水平。该种冷捣糊一年四季不需预热就可使用,既减轻工作强度,又降低了筑炉成本。 相似文献
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用蒽油作稀释剂的冷捣糊性能 总被引:5,自引:2,他引:3
铝电解槽底部炭块的接缝部位是铝电解槽内衬中最薄弱的地方,底糊质量的好坏直接关系到铝电解槽的寿命。与热捣糊相比,冷捣糊有许多优点。本文在实验室条件下,制取了用蒽油一煤沥青作粘结剂的冷捣糊试样,测定了其性能。通过碳化率的测定及其与热捣糊性能的对比,得出了结论。 相似文献
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选用石英粉作为耐火骨料,以硅溶胶和PVA为复合粘结剂,以钠基膨润土和羧甲基纤维素(简称CMC)为复合悬浮剂,制备出铸铁件消失模水基涂料;研究了石英粉耐火骨料的粒度分布对消失模铸造涂料性能,特别是透气性和粘度的影响.结果表明,为了得到性能优良的涂料,在配制涂料时应使用粒度集中的耐火骨料. 相似文献
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粘结剂对骨料的浸润性能是影响铝电解槽阴极炭质内衬混捏糊料质量的重要指标。利用静态浸润性能测定装置,分别研究了不同骨料种类和粒径、温度、加热时间、振实时间下高温煤焦油对阴极炭质内衬骨料浸润性的变化规律,并测定了骨料的比表面积和堆积密度。结果表明,随着骨料粒径的减小和振实时间的增加,比表面积增大,骨料趋于紧密堆积,煤焦油对阴极炭质内衬骨料的浸润性显著降低;随着温度的提高和加热时间的延长,煤焦油的黏度急剧下降,毛细管作用加强,煤焦油对阴极炭质内衬骨料的浸润性大幅度增加;在相同工艺参数的条件下,煤焦油对电煅无烟煤的浸润性均优于沥青焦。 相似文献
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在本文中,研究了添加剂的粒度和AgSnO2触头材料的性能之间的关系。Bi2O3、TiO2和CeO2被选作添加剂,并且四种粒度被选择,与此同时添加剂的比例通过润湿性试验获得。AgSnO2 触头材料通过粉末冶金法制备。对掺杂不同种类不同粒度的AgSnO2触头材料的物理和电接触性能进行了研究,结果表明三种添加剂(Bi2O3、TiO2和CeO2)的粒度对触头材料性能的影响趋势是一致的,并且细的添加剂颗粒有利于AgSnO2触头材料性能的改进。随着添加剂粒度的减小,AgSnO2触头材料的物理和电接触性能都得到了提高,并且添加剂的最佳粒径200nm。结果表明AgSnO2触头材料的性能可以通过选择添加剂的最佳粒度改进。 相似文献
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选用TiO2作为触头材料的添加剂,采用粉末冶金法制备了6种不同第二相(SnO2)粒度的AgSnO2和AgSnO2/TiO2触头材料。研究了2种触头材料的润湿性和电接触性能。用座滴法测量了Ag与SnO2之间的润湿角,并表征了材料的湿润性,使用JF04C电接触触头材料测试系统对材料电接触性能进行了测试,分析了不同第二相粒度的触头材料的润湿性和电接触性能的变化规律。结果表明,当第二相粒度为100~300 nm时,2种触头材料的性能均优于其它粒度的触头材料。 相似文献
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Santosh Kumar Sabuj Mallik Ndy Ekere Jaepil Jung 《Metals and Materials International》2013,19(5):1083-1090
Stencil printing for flip chip packaging using fine particle solder pastes is a low cost assembly solution with high throughput for fine pitch solder joint interconnects. The manufacturing challenges associated with both solder paste printing increases as electronic device size decreases due to trend of miniaturization in electronic components. Among multiple parameters, the two most important stencil printing parameters are squeegee pressure and printing speed. In this paper, the printing behavior of Pb free Sn-3Ag-0.5Cu solder paste with a particle size distribution of 2–12 μm for wafer level bumping using a stencil printing method (stencil opening dimension ?30 μm) was evaluated by varying the printing speed and squeegee pressure to fabricate solder bumps with a sub 100 μm size. The optimal squeegee pressure and print speed for the defect free printing behavior and fairly uniform size distribution of reflowed paste were found to be 7 kgf and 20 mm/s, respectively. The average size of the reflowed printed paste decreased with the increasing squeegee pressure. 相似文献
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The filling powder, as a part of the feedstock in cored wires, directly influences the particle formation, in-flight particle behavior, the coating microstructure, and consequently the behavior of the desired coating, produced by twin wire arc spraying (TWAS). In this work, the effect of the particle size distribution of the filling powder in cored wires was studied. The process parameters were changed for different intervals of particle size distributions. Arc fluctuations were measured and found to be higher at smaller particle sizes. The in-flight particles showed a higher velocity when powders with smaller grain sizes were used and higher particle temperature when bigger grain sizes were used. The splats tended to form a regular disk shape in the case of smaller grain sizes. This investigation studied the important effect of using cored wires and the filling powders grain sizes on the TWAS process. 相似文献
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Ni-P金刚石化学复合镀层制备及摩擦磨损性能分析 总被引:1,自引:1,他引:0
目的研究不同粒径微米金刚石对Ni-P金刚石化学复合镀层摩擦磨损性能的影响。方法选择出一组优良的Ni-P化学镀工艺参数,在镀液中分别加入不同粒径的金刚石微粒,制备含不同粒径微米级金刚石颗粒的化学复合镀层。用SEM和XRD,观察并分析了不同粒径金刚石对热处理前后Ni-P金刚石化学复合镀层微观形貌和组织结构的影响;通过硬度和摩擦磨损实验,研究了不同粒径金刚石颗粒对复合镀层硬度及摩擦磨损性能的影响。结果制备的复合镀层厚度为30μm左右,金刚石质量分数达到21%~25%,且金刚石均匀分散在Ni-P镀层中。热处理前镀层为非晶结构,经过400℃×2 h的热处理后,镀层晶化为硬度更高的Ni3P。金刚石能提高镀层硬度,其中粒径为9μm的复合镀层硬度最高,达到1261HV。Ni-P金刚石复合镀层的摩擦系数为0.4~0.52,随着金刚石粒径的增大,摩擦系数不断减小。金刚石使镀层的磨损机制发生了变化,随着金刚石粒径的增大,硬质合金球的磨损加剧。结论随着金刚石粒径的增大,镀层硬度增加,摩擦系数减小,耐磨性增大。 相似文献
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The polymer-ceramic composites of epoxy resin (EP) and barium titanate (BT) were prepared.BT powders of different BT particle sizes from 100 nm to 1 μm were used in the preparation.The dielectric properties, such as dielectric constant, dielectric loss and electrical breakdown strength, of the EP/BT composites were studied.The morphology of the composites was characterized by the means of scanning electron microscopy (SEM).The results show that the dielectric constant of the composites is much higher than the epoxy matrix at frequency range from 1 kHz to 10 MHz, and it is also obviously dependent on the size of BT particles.The electrical breakdown strength of the composites decreases with the increase of the BT content.The dependence of electrical breakdown strength on BT particle sizes was also discussed. 相似文献
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超微LaMnO3的合成与导电性研究 总被引:1,自引:3,他引:1
采用柠檬酸盐热解法合成了LaMnO3超微粉末。经X射线衍射分析表明,所合成的LaMno3为单相,属于六方晶系。实验发现,LaMno3的平均粒径随焙烧温度的增加而明显地增大。首次研究了超微LaMnO3的电阻率随粒径的变化,发现LaMnO3的室温电阻率随粒径的增加而减小,导电活化能随粒径的减小而变小。 相似文献
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银钯合金粉末制备的电子浆料以其优异的导电、抗银离子迁移、可焊耐焊性,成为低温共烧陶瓷工艺(LTCC)配套用关键电子浆料之一。比较研究两种不同特性的银钯合金粉制备的浆料与Ferro A6生瓷带共烧后的匹配性、电学性能、附着力、可焊性与耐焊性等性能。高振实、大粒径的银钯合金粉制备的浆料与Ferro A6生瓷带共烧平整,电极膜层平整光滑,各项性能表现出优异。粒径较小的银钯合金粉,与瓷料烧结收缩率不匹配,基板翘曲严重,膜层起皱,导电性及可焊耐焊性相对较差。 相似文献