"胶乳法"氯化天然橡胶薄层干燥影响因素的研究

采用二次回归正交设计方法,对“胶乳法“氯化天然橡胶(CNR)进行薄层干燥试验.分析了热风温度、风速和物料的粒径等因素对干燥速率、干燥后物料性能的影响规律,确定了影响物料薄层干燥速率各因素的主次,提出了较佳的干燥工艺和合理的性能参数.     

火焰原子吸收光谱法测定硅粉中的铜

介绍了用火焰原子吸收法测定工业硅粉中微量铜的具体方法和过程，同时也给出了最佳实验条件。实验中采用新的样品处理方法，得到了令人满意的结果。其中样品回收率为99．8％—104．0%，相对标准偏差为0．31％—0.38％。本方法在实际应用过程中，简单、快速、     

凝胶法片状莫来石粉的制备及应用

采用拟薄水铝石和非晶态超细SiO_2微粉为原料。以溶胶-凝胶工艺制取莫来石凝胶,通过干燥、煅烧研制得片状结晶莫来石粉。初步研究了凝胶法莫来石粉在钛酸铝陶瓷和烧结刚玉砖中的应用。实验结果表明:凝胶粉起到了促进烧结、降低烧成温度的作用,并使钛酸铝——莫来石复相陶瓷和刚玉砖的强度得到了显著提高。     

Zinc-rich powder coatings corrosion in sea water: influence of conductive pigments

The effect of addition of conductive pigments like carbon blacks on the corrosion behavior of zinc-rich powder paints coated steel in artificial sea water was investigated. Open circuit potential measurements were used to characterize the cathodic protection ability and duration. Micro-Raman spectroscopy analysis was performed in order to identify the corrosion products and to follow the penetration of the solution inside the coatings.

Two different effects were pointed out: an increase of the porosity induced by carbon addition and a galvanic action between zinc and carbon pigments. The performance of the powder coatings, strongly improved if the carbon amount is sufficient, was compared to the one reported for solvent-based zinc-rich paints.     

硅氮聚合物交联的室温硫化橡胶的研究Ⅰ．热稳定性的研究

本文利用硅氮聚合物作文联剂使双组分缩合型室温硫化硅橡胶在不需要催化剂存在下就能交联硫化，通过时硫化胶老化后的热失重、交联密度和力学性能的测定，表明这种硫化胶的耐温性能由２００℃提高到３５０℃。对硫化胶的降解动力学研究表明：降解反应活化能由７０ｋＪ／ｍｏｌ提高到３３０ｋＪ／ｍｏｌ，这是由于消除了端基引发的主链降解。     

天然酯绝缘油与变压器常用橡胶材料的相容性研究

通过天然酯绝缘油与变压器常用的丁腈橡胶、丙烯酸酯、氟橡胶及氟硅橡胶等材质橡胶的相容性试验,分析了在试验中引起橡胶材料性能变化的原因。     

等离子喷涂送粉参量对粉末粒子运动行为的影响分析

为研究等离子喷涂设备送粉参量变化对粉末粒子运动行为的影响,通过数学计算给出了粉末粒子初速度及运行轨迹的一些解析计算结果.结果表明粉末粒子喷出初速度随送粉气流量的增大呈线性增大,随送粉管直径增大呈指数减小,而且与密度和粒径的指数幂成反比关系.当粉末粒子粒径为75μm时,Ni金属粉末的最佳送粉参量为:送粉气流量0.2m3/h,送粉管直径1.5mm;Al2O3陶瓷粉末最佳送粉参量为:送粉气流量0.3m3/h,送粉管直径1mm.该项研究工作为选择最佳送粉参量和控制粉末粒子在等离子流场中的运动提供了依据.     

粉末烧结体镦粗致密与成形的有限元分析

选择典型的镦粗工艺对粉末烧结坯的致密与成形行为和规律进行了研究，提出了多孔材料的致密模型并简要介绍了多孔材料的塑性理论。然后，采用有限元法模拟了不同镦粗压下量的烧结坯的致密与成形过程。密度与等效应变分布的一致性表明，烧结坯的致密强烈依赖于材料的塑性变形。     

Electroless coating of Permalloy powder and DC-resistivity of alloy composites

A high-resistivity coating of Permalloy (Ni–17.81Fe–1.97Mo wt.%) powders for soft magnetic composites, SMC, was developed and characterized. The coating was made using the electroless plating method employing an aqueous solution of sodium and nickel phosphates. The chemical process led to the formation of a layer up to 1 μm thick deposited on each particle surface and composed of a mixture of Ni(OH)₂, P₂O₅ and NaPO₃ compounds, as shown by X-ray photoelectron spectrometry and X-ray powder diffraction studies. The effect of coating on electrical DC resistivity was evaluated on SMC obtained mixing the metal, coated or uncoated, and thermoplastic polymer PEEK (polyetheretherketone) powders, pressing the mixture at 800 MPa and heating in air up to melting the polymer (380–410 °C). The SMC made with coated powders showed an increase in resistivity of more than two orders of magnitude compared to that obtained with uncoated powders when the polymer ranged between 0.5 and 1.5 wt.%. This difference prevails in comparison with sintered materials processed at the same pressure and sintering in hydrogen at 1350 °C. Thus, this process would restrict the eddy currents which affect the performance of soft magnetic products for AC applications.     

粉末冶金法浸入式发泡制作泡沫铝的试验研究

研究了浸入法制备泡沫铝的发泡新工艺以及工艺参数对发泡效果的影响，得出以工业纯铝粉和而H2粉为原料，制备气泡均匀、孔隙可控的泡沫铝的工艺参数为：浸入温度为680～760℃，浸入时间为10～30s，保温发泡时间为10～60s。研究结果表明，粉末冶金法浸入式发泡制备泡沫铝的效果好、结构均匀、TiH2利用率高，是一种有较好开发前景的新制备方法。