硬质合金与铁基复合材料热等静压扩散连接

以烧结结态硬质合金和粉末态铁基复合材料为连接对象，研究了两种材料的热等静压扩攻连接工艺，获得了直接连接接头和加镍作中间过渡层的间接连接接头，考察了接头的结合界面形貌，界面的元素扩散和界面结合强度。     

颗粒表面改性法制备PTC粉体的研究

本文介绍了一种通过液相颗粒表面改性技术添加二次掺杂物来制备ＰＴＣ粉体的新方法。即将烧结助熔剂Ａｌ２Ｏ３，ＳｉＯ２以及受主杂质ＭｎＯ采用溶液形式，包裹在ＢａＴｉＯ３基粉体颗粒表面进行改性，由此可以得到二次掺杂物Ａｌ２Ｏ３、ＳｉＯ２和ＭｎＯ分布均匀的ＰＴＣ粉体。     

An examination of the effect of composite constituent properties on the notched-strength performance of composite materials

The effect of matrix and fiber properties on the strengths and failure processes of notched, continuous-fiber composite specimens has been investigated. Bearing, open and filled hole tension and compression tests were conducted on AS-4/3501-6, IM-8/3501-6, AS-4/APC-2 and IM-8/APC-2 specimens. Failure characteristics of tested specimens were studied by fractographic techniques. Failure progression was tracked by means of incremental loading, radiography and fractographic inspection.     

Al2O3/TiB2/SiCw三元复合材料的力学性能及显微结构

以Al₂O₃为基体,SiC晶须和TiB₂颗粒两种增韧剂,采用热压烧结工艺制备了Al₂O₃/TiB₂/SiC_w三元复合陶瓷材料。研究了热压工艺参数对材料致密度的影响和晶须含量对该复合材料的力学性能和显微结构的影响。结果表明;随晶须含量的增加,该复合材料的热压温度和保温时间需要相应的增加;晶须拔出、裂纹偏转和晶须的桥接为该复合材料的主要增韧机理;随晶须含量的增加,该材料的室温断裂韧性增加;该材料的断裂韧性随温度的升高而呈增大趋势,并且晶须含量越高,材料的高温断裂韧性增幅越大。     

Thin conducting polypyrrole film on insulating surface and its applications

An electrically conductive plastic material was obtained by the polymerization of pyrrole on insulating polymeric materials and nylon cloth impregnated with the oxidant by vapour phase technique, resulting in a uniform, smooth and adherent coating of conducting polymer having a surface resistance ranging from 200 Ω/□ to 20 kΩ/□, which makes it suitable for applications as an antistatic material.     

基体改性对C/C复合材料性能影响的研究(一)

本文从C/C复合材料的基体入手,研究了基体沥青、焦炭中添加氧化物的工艺条件及其在复合材料中的作用.结果表明,添加氧化物对基体改性,不仅能提高C/C复合材料的高温抗氧化性,也能对其它性能带来很大影响.只要控制适当的工艺条件,就可以得到高性能的C/C复合材料.     

The effect of fibre alignment on composite strength: II. The strength of angle-ply laminates

Experiments have been carried out on relatively wide angle-ply laminate samples with very short gauge lengths. These proved to be very much stronger than samples tested in earlier work, and which form the basis for our present design with these materials. It is highly likely that the early results for strength were more indicative of edge effects than true laminate strength. This is confirmed by data from tests on pressurized tubes. A review of the literature on this shows that such tests produced results which can be an order of magnitude higher than the early laminate tests. Thus our design calculations could well be severely underestimating the potential strength of angle-ply laminates. This may be having serious consequences for the aerospace industry, through the use of design criteria for strength which may be too conservative. Single-fibre experiments may pave the way for more realistic estimates of angle-ply laminate strengths. These indicate that a simple one-third power rule can be used to estimate the potential strength. However, this is purely ad hoc at present, and needs to be put on a firmer footing through both theoretical and experimental studies. Furthermore, if this approach is adopted, edge effects will still have to be allowed for, and estimated on the basis of the aspect ratio of the part.     

50kg／m钢轨轨底缺陷的检验和分析

钢轨轨底缺陷有三种：底伤、结疤和底裂缺陷。取２０根有底缺陷５０ｋｇ／ｍＵ７１Ｍｎ钢轨做试样，通过低倍、断口、金相检验和扫描电能谱分析，详细描述了轨底缺陷的宏观和微观特征，研究出钢轨轨底缺陷出现的规律臁其产生的原因。通过对比试验，发现淄博１号保护渣有利于改善钢锭表面质量，提高钢轨一级品率。     

Pultruded fibre reinforced polyurethane composites II. Effect of processing parameters on mechanical and thermal properties

This paper presents a novel process for the fabrication of pultruded polyurethane (PU) composites. The effects of the processing parameters on the mechanical properties (flexural strength and flexural modulus, etc.) and thermal properties (HDT) of the fibre reinforced PU composites by pultrusion have been studied. The processing parameters investigated include pulling rate (in-line speed), die temperature, filler type and content, and post-cure time and temperature. Results show that the composites possessed various optimum pulling rates at different die temperatures. On the basis of the DSC diagram, the swelling ratio, the mechanical properties and the thermal properties of composites, the optimum die temperature can be determined. It is found that the mechanical and thermal properties increase with filler content for various types of filler. The mechanical and thermal properties increase at a suitable post-cure temperature and time. Furthermore, the properties which decreased due to the degradation of composite materials for a long post-cure time will be discussed.     

佛尔哈德法测定氯化除汞上清液中的氯量

控制pH4-6，用锌粉还原氯化除汞上清液中的汞（Ⅱ）离子，取置换后液加入过量的硝酸银标准溶液，以硫酸铁铵溶液作指示剂，用硫氰酸钾标准滴定溶液滴定来测定氯量。该方法的检出限：0．25mg／100mL，回收率：98％-101％。