共查询到20条相似文献,搜索用时 62 毫秒
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介绍了一种粉尘湿润剂的性能测定方法。该方法是将一定质量的粉尘分散在制备好的湿润剂溶液中并搅匀,经过短时间的沉淀后,采用高精度激光粒度分析仪,测定悬浮在溶液中的粉尘粒径和分散度。结果表明:悬浮在溶液中的粉尘颗粒大小和分散度随着溶液中的湿润剂类型、湿润剂质量浓度和沉淀时间的不同而变化。因此,应用高精度激光粒度分析仪可以间接地研究粉尘湿润剂的性能,从而达到开发新的粉尘湿润剂的目的。以湖南某铅锌矿矿尘为研究对象,对粒径小于20μm的微尘进行实验,证明了该测定方法的可行性,并获得一组抑制铅锌矿矿尘的湿润剂配方。 相似文献
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主要介绍了基于相同的校准方法,采用两种不同的试验粉尘ACFTD与ISO MTD对高、中、低3种不同精度的滤材进行过滤效率试验,得出ACFTD与ISO MTD对不同精度滤材过滤效率的影响程度。 相似文献
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为了评价水玻璃砂用振动法再生的效果,作者进行了三种试验。当旧砂颗粒表面的粘结层受振动力作用剥落,并以粉尘的形式通过粉尘计,表示再生程度的粉尘浓度以数字的形式连续显示出来。在作者的实验中,粒度分析是由映象分析装置来进行的;氧化钠的含量是用改进的标准酸消耗量方法测定。分析的结果表明,水玻璃砂旧砂预处理后,再用干式振动法进行再生是有效的。作者认为,分析砂粒度的筛分法有可能逐步被映象分析法取代,而测定氧化钠成份的滴定法应做进一步的研究。 相似文献
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不同压制方法所得预制品的发泡性质研究 总被引:1,自引:0,他引:1
对冷压法,热压法和挤压法三种方式压制的预制品的发泡性质进行了试验研究.结果表明,在相同的发泡温度下,不同压制方法所得试样发泡效果不同.分析表明,预制品制备方式对其发泡效果和行为有显著影响,挤压法得到的预制品由于颗粒之间结合最紧密,所以其发泡效果最好. 相似文献
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The initial rapid wetting of a solid surface by a liquid phase is an important step in many industrial processes. Liquid-phase sintering of powder metallurgical steels is one such industrial process, where metallic powders of micrometer size are used. Investigating the dynamic wetting of a high-temperature metallic drop of micrometer size experimentally is very challenging. Here, a phase-field-based numerical model is first implemented and verified by accurately capturing the initial dynamic wetting of millimeter-sized metal drops and then the model is extended to predict the dynamic wetting of a micrometer-sized metal drop. We found, in accordance with recent observations, that contact line friction is required for accurate simulation of dynamic wetting. Our results predict the wetting time for a micrometer-sized metal drop and also indicate that the dynamic wetting patterns at the micro- and millimeter length scales are qualitatively similar. We also found that the wetting process is much faster for a micrometer-sized metal drop compared to a millimeter-sized metal drop. 相似文献
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Experiments are performed to observe capillary flow in grooves cut into copper surfaces. Flow kinetics of two liquids, 1-heptanol and eutectic SnPb solder, are modeled with modified Washburn kinetics and compared to flow data. It is shown that both liquids flow parabolically in narrow V-grooves, and the data scale as predicted by the modified Washburn model. The early portions of the flow kinetics are characterized by curvature in the length vs time relationship which is not accounted for in the modified Washburn model. This effect is interpreted in terms of a dynamic contact angle. It is concluded that under conditions of rapid flow, solder spreading can be understood as a simple fluid flow process. Slower kinetics, e.g. solder droplet spreading on flat surfaces, may be affected by subsidiary chemical processes such as reaction. 相似文献
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Two bodies, e.g. grains with a certain surface contour, are assumed to be in contact at a plane interface, e.g. a common grain boundary with an arbitrary inclination relatively to the surface and with zero mobility and diffusivity. A groove appears due to surface diffusion along the triple line, i.e. the intersection line of the two surfaces and the grain boundary. The thermodynamic extremum principle is applied to derive the evolution equations for the surfaces of both bodies as well as the contact conditions at the triple line. Applications to grooving and wetting are demonstrated and compared with the results from the literature. The simulations indicate that the groove root angle can be significantly different from the value of the dihedral angle calculated from the equilibrium condition for the specific grain boundary and surface energies. Moreover, it is demonstrated that the groove angle is dependent on the kinetic parameters, e.g. surface diffusion coefficients of individual grains. 相似文献
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K.M. Martorano M.A. Martorano S.D. Brandi 《Journal of Materials Processing Technology》2009,209(6):3089-3095
Wetting balance tests of copper sheets submerged in tin solder baths were carried out in a completely automatic wetting balance. Wetting curves were examined for three different values of sheet thickness and four different solder bath temperatures. Most of the wetting curves showed a distorted shape relative to that of a standard curve, preventing calculation of important wetting parameters, such as the wetting rate and the wetting force. The wetting tests showed that the distortion increased for a thicker sheet thickness and a lower solder bath temperature, being the result of solder bath solidification around the submerged sheet substrate. 相似文献
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Template wetting is a simple, solution based nanofabrication method that has been shown effective for a wide range of polymers. Like other solution based polymer processing methods, it is reasonable to expect that the choice of solvent will have a significant impact on the chain orientation in the final solid structure. Here we examine the impact of wetting solvent on the properties of 100 nm diameter poly(3-hexylthiophene) (P3HT) nanotubules made via template wetting. The degree of alignment of the P3HT backbone with the nanotubule axis as observed through dichroism in the FTIR spectrum was observed to depend on the strength of polymer–solvent interaction forces, observed experimentally through thermogravimetric analysis experiments. This solvent effect was not observed in other properties as neither the UV–Vis absorbance nor the hole mobility was observed to depend significantly on the wetting solvent. It is believed that the rigid rod structure and large side chain limited the degree of increase in the effective conjugation length and preventing even the aligned chains from being more tightly packed as would be necessary for an increase in inter-chain π-bond interactions sufficient to impact these performance characteristics of the material. 相似文献
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This paper focuses on spontaneous infiltration by liquid metals in reactive metal/ceramic systems. Two cases of reactive infiltration, where a molten silicon drop is in contact with two different porous bodies, graphite and (oxidized) silicon nitride, are briefly described and discussed. For each solid, the dynamics of wetting on the solid surface is compared to the dynamics of infiltration into the porous medium in order to determine the common points and the main differences between these two processes. 相似文献
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利用SEM和XRD研究了Ni-Cr-Co-W-Mo-Ta-B合金粉末钎料的微观结构,利用润湿测量系统研究了Ni-Cr-Co-W-Mo-Ta-B合金熔体在镍基高温合金基片上的润湿行为。结果表明,Ni-Cr-Co-W-Mo-Ta-B合金由M23B6和镍基固溶体γ相组成,合金粉末呈球形,颗粒的剖面呈树枝状形态;合金熔体在1140℃和1160℃润湿镍基高温合金基片时,具有良好的润湿性。 相似文献
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A diffuse-interface model of reactive wetting with intermetallic formation is developed that incorporates fluid flow, phase change and solute diffusion. The model is based on the total molar Gibbs energy of a ternary system with four phases. Numerical simulations were performed using a mesh-adaptive finite element method, revealing the complex behavior of the reactive wetting process. The model was verified against equilibrium states derived from the classical phase diagram and from interface energy considerations. Dynamic results show that the intermetallic can either precede or follow the spreading liquid droplet, depending on the time and the choice of interface energy and kinetic coefficients. Despite this difference, the spreading rate was not affected for the cases considered. 相似文献
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The role of intermetallics in wetting in metallic systems 总被引:3,自引:0,他引:3
Pavel Protsenko Anne Terlain Vladimir Traskine Nicolas Eustathopoulos 《Scripta materialia》2001,45(12):1439-1445
Formation of intermetallic seems to improve strongly wetting of a solid metal by a liquid one. The aim of this study is to identify the reasons of this improvement. For this purpose, wetting of Fe is determined at the same experimental conditions for two liquid metals, one reactive (Sn), the other non-reactive (Pb). 相似文献
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Jinan Cao Alan N. Buckley Alan Tomsett 《JOM Journal of the Minerals, Metals and Materials Society》2002,54(2):30-33
To produce structurally soundcarbon anodes for use in aluminum smelting, a strong bond between filler and binder coke is necessary.
Bond strength results from mechanical interlocking and adhesion of the binder coke to the filler coke. Critical for creating
such bonds is the ability of the pitch to wet the coke surface and penetrate the coke porosity during mixing and forming.
Wettability is normally assessed from the pitch behavior during the initial stages of a penetration test. In the test, the
observed contact angle between a pitch droplet and a bed of fine coke particles is recorded as the temperature is increased.
The temperature at which this contact angle becomes 90° is referred to as the wetting temperature of the pitch. The penetration
test may be useful to identify pitch and coke combinations that are unlikely to produce baked anodes of acceptable quality
with standard paste preparation conditions. It does not, however, provide a measure of the true wettability of a coke by a
pitch. The isothermal penetration experiments reported here demonstrate that the observed contact angle of a pitch against
a coke bed changes continuously from >90° to <90°, even to 0‡, at a temperature much lower than the wetting temperature derived
from the penetration test. The requirements for the measurement of a true contact angle and the difference between the concepts
of adhesion and wetting are discussed. 相似文献