金属泡沫材料研究进展

综述了金属泡沫材料的各种制备方法。液相法制备金属泡沫材料包括气体吹入法、固体发泡剂法和固体—气体共晶凝固法、熔模铸造法、渗流铸造法、喷射沉积法以及粉末加压熔化法等制备方法。采用金属粉末烧结法、浆料发泡法等制备工艺可以从固相制备金属泡沫材料。电沉积法以及气相沉积法可用于制备高孔隙率的金属泡沫材料。最后简要总结了金属泡沫材料的应用。     

物流公司配送绩效评价模型研究

基于物流公司配送绩效评价指标体系，在粗选方案后，采用一种客观的方法——熵法来确定权值，然后运用线性加权法、欧式范数法、TOPSIS法和线性分配法4种方法进行排序，再运用Spearman's的排名相关性系数对4种方法进行筛选，最后采用线性加权法、欧式范数法、TOPSIS法3种方法平均得出最后的结论。     

李级数法与Runge-Kutta法

对线性自治系统证明了二阶、四阶李级数法分别与Runge—Kutta法中二级二阶改进Euler法和四级四阶经典R—K法的一致性；说明了李级数法和Taylor级数法的一致性，但两者计算导数的方法不同，导致不同的应用价值。分析了李级数法在求解非线性问题时的优越性。     

聚合物微胶囊的研究与应用进展

综述了模板法、层层自组装法、聚合相分离法、界面聚合法、原位聚合法、喷雾干燥法等合成聚合物微胶囊方法,论述了聚合物微胶囊在各个领域的应用,并展望了可能的发展趋势。     

ZnS基电致发光薄膜及其制备方法

ZnS是一种优良的光电材料并获得了广泛的应用。介绍了ZnS基薄膜电致发光器件的发展历史、结构及发光机理,主要讨论了ZnS基发光薄膜及蒸发法、溅射法、化学气相沉积法、外延法和溶胶-凝胶法等制备方法的最新研究进展,指出了目前存在的问题及今后的发展趋势。     

水声材料小样品声学性能不同测试方法比较

介绍了水声材料声学性能的3种不同的测试方法，通过对同种样品的性能测试，分析了不同测试方法的优缺点。结果表明，与行波法相比，脉冲法和驻波法测试可靠性较高。      

超细高岭石粒径测试方法对比研究

以甲氧基嫁接高岭石复合物为前驱体,利用插层-剥片法对高岭石片层进行剥离,制得超细高岭石样品;以张家口高岭石原矿为对比测试样品,分别采用激光法、图像法和电阻法测试高岭石原矿样品和超细高岭石样品的粒径。结果表明:3种测试方法均可用于高岭石的粒径测试,测试结果相差较小,粒径变化趋势一致;高岭石原矿粒度分布分散,超细高岭石粒度分布集中;在张家口高岭石原矿粒径的测试中,激光法测试结果偏大,电阻法测试结果偏小,图像法测试结果居中,优先选择图像法;在超细高岭石粒径的测试中,图像法测试结果偏大,电阻法结果偏小,激光法测试结果居中,优先选择激光法。     

超微粉制备技术及其进展

论述了近年来微粉的各种制备方法及其进展，包括固相法，液相法和气相法的原理，种类和特点，并指出了超微粉备技术和发展方向。     

油气储运中废气污染与回收的研究

油品蒸发给从石油开采到成品油使用整个过程带来隐患，环境中油蒸气达到一定浓度易引发火灾、环境污染。油品蒸发还会造成大量油品浪费，并且因油品中轻组分的蒸发，使油品质量下降。本文分析了油品储运过程中蒸发损耗产生的机理，介绍了吸收法、吸附法、冷凝法、膜分离法和各种组合集成法的可行性方案，探讨了各种油气回收技术的优缺点和适用范围。     

采用新型高效脱氧剂生产高纯氮

我们知道，工业气体常见的纯化方法主要有化学反应法(又称催化反应法)，选择吸附法，低温精馏法，金属吸气法和薄膜扩散法等。在实际应用中，往往是几种方法同时采用，如用低温精馏法 选择吸附法来制职纯氩气。本文介绍一种化学反应法 吸附法——采用新型高效催化脱氧剂3093和3093A脱氧，并用5A分子筛吸附杂质，制取高纯氮的应用实例。     

Microstructural refinement of Al-10.2%Si alloy by intensive shearing

Al-10.2%Si alloy when cast near the liquidus temperature has tremendous potential for producing fine grain structure. However, for casting applications, it requires casting at higher superheating, where this alloy results in large dendritic grain structure. Here, we show that, by applying intensive shearing to the liquid metal prior to casting, dendritic growth can be largely suppressed and fine grain structure can be achieved at higher casting temperature.     

细晶铸造K418合金叶片EI

研究了K418合金细晶形成的方法,细晶叶片的铸造工艺参数及其获得的晶粒度等级,并讨论了细晶形成的原理。     

Role of grain refining in hot cracking and macrosegregation in direct chill cast AA 7075 billets

Abstract

Direct chill (DC) casting experimental results are presented for an Al–Zn–Mg–Cu alloy with and without grain refining by attempting the inoculant addition either in the furnace or in the launder at two different casting speeds. Despite considerable structural refinement macro segregation remains unchanged with grain refining at a lower casting speed. Hot cracking, on the other hand, is totally prevented at this casting speed. Depending on the grain refining practice, either hot tears do not appear at all or prior cracks existing in the non-grain refined billet are completely healed. At a higher casting speed, the severity of segregation increases. The hot cracking tendency, however, has shown a distinct difference with grain refining method, with furnace-refined alloy resulting in a crack-free billet. But the billet grain refined in the launder exhibited hot cracking. Overall, these experimental results confirm the beneficiary effect of grain refining on hot cracking.     

Analysis of solidification in Bridgman furnace as simulation of DC casting of aluminium alloy slabs

Abstract

The vertical Bridgman directional solidification equipment has been used in several investigations to simulate direct chill casting of wrought aluminium alloys. As a basis for such investigations and alloy developments, it is important to have an understanding of the performance of the furnace used during simulation of the casting conditions. In this investigation the thermal conditions in the furnace have been analysed in detail, both by measurements and by mathematical modelling. The growth characteristics of the furnace, such as gradient, growth rates and cooling rates have been compared to conditions in large ingots. The direct chill casting conditions, which the simulations have been compared to, are casting of slabs of 330 and 600 mm thickness of an aluminium AA3003 type alloy. The results show that the experiments are able to simulate the cooling conditions in the ingots except from the surface zone. Comparisons of the microstructures have been made and a good agreement has been obtained for structure parameters such as grain size and DAS.     

细晶铸造K418合金晶粒度的显示与评级方法研究

本文研究了Ｋ４１８合金细晶铸件晶粒度的显示和评级方法，实际应用证明是可行的。     

近液相线铸造过程中近球形α相的形成机理

为从理论上弄清近液相线半连续铸造过程中铝合金半固态组织形成的基本规律和机制,研究了浇注温度、铸造速度和冷却强度等工艺参数对6061合金初生α相演变的影响,根据金相检测和多尺度计算机模拟结果,分析了近球形α相的形成机理.实验发现,在浇注温度为657℃、铸造速度为150 mm/min、冷却水流量为0.05 m3/min时可...     

A Simple Method for Grain Refinement of Pure Aluminium

In order to produce the fully equiaxed and fine grained pure Al, a simple casting process that used cooling slope was examined and compared with conventional casting process under same casting conditions. By using cooling slope, grains over the whole section of castings were suddenly refined and ability of grain refinement kept up at very high mold temperature up to 550癈 in examined casting conditions.     

细晶铸造K418合金热等静压后热处理制度的研究EI

通过力学性能和合金组织比较了三种热处理制，确定了细晶铸造Ｋ４１８合金热等静压后所使用的热处理制度。     

空心管坯电磁离心过程的数值模拟

用有限元法模拟了铸造合金的流动和热量传输过程中瞬态速度场和温度场的分布,研究了电磁场强度和离心机转速对电磁铸造空心管坯的影响.结果表明,电磁搅拌引起的熔体相对运动是凝固过程中晶粒细化的主要原因.最优的电磁搅拌条件:转速1200 r/min,磁场强度为0.08 T,磁场持续加载25 s.在一定的转速和磁场强度条件下电磁离心铸造的温度场和凝固时的温度梯度对凝固组织有重要的的影响.合金液的外层,温度梯度达到最大值,铸件的温度下降得快,容易形成细小的等轴晶.     

Replication casting of open-cell AlSi7Mg0.3 foams

A typical aluminum alloy for casting (AlSi7Mg0.3) was used to produce open-cell foams by replication of a salt precursor. The process was set to minimize complexity and costs of the casting operations: the preform sintering was avoided and mold temperature lower than the eutectic temperature of the alloy was used. Open-cell foams with a relative density about 35% and high compressive strength resulted. Material analyses showed that, in replication casting, the material response to the process is optimal and a homogeneous and fine grain size distribution is visible in the foams.