稀士对铁合金喷熔层的成分、组织及各种耐磨性的影响

本文主要研究了稀土对铁基合金喷熔层不同层深的成分、组织结构及各种耐磨性的影响规律及作用机制。试验结果表明，稀土元素不但能细化喷熔层的基体组织，同时，随稀土含量的变化，硬质相的形貌、尺寸及分布规律均有所变化；并且能加速基材和喷熔层的扩散，导致喷熔层不同深处的成分也发生变化。因此，稀土对喷熔层耐磨性的影响是多方面的。     

粉体MnO2电极的循环伏安研究

用循环伏安法对粉体MnO_2(包括电解MnO_2和天然锰矿)电极在KOH水溶液中进行了研究,讨论并确定了实验条件。结果表明,电解MnO_2与天然锰矿由于结构不同,在碱性溶液中氧化还原的机理也不同;电解MnO_2→Mn_2O_3→Mn(OH)_2,而天然锰矿则一步还原成Mn(OH)_2。     

Microstructural evolution of hybrid aluminum matrix composites reinforced with SiC nanoparticles and graphene/graphite prepared by powder metallurgy

The dispersion of ceramic nanoparticles is of significance to the microstructure and properties of particulate reinforced metal matrix composites.In this study,two hybrid enhancers,SiC-graphite and SiC-graphene nanosheets(GNSs),were incorporated into aluminum matrix composites using powder metallurgy.The dispersion of the reinforcements and microstructural evolution of the composites were characterized by using Scanning Electron Microscopy,X-Ray Diffraction,Transmission Electron Microscopy,and Raman spectroscopy.The results show that thin GNSs accelerated the deformation of the aluminum particles,and defects were introduced into the carbonaceous phases during the ball milling process.Al_4 C_3 needles generated during hot pressing,and were observed to bridge the aluminum grains.Compared with graphite,GNSs were more uniformly dispersed throughout the composite,which in turn restrained grain growth.As a result,a nanostructured composite(57.7 nm) was successfully produced upon the addition of SiC-GNSs.     

对两种粉料包装机性能的分析与改进

本文对两种国产粉料包装机性能作了对比分析，指出了各自的优缺点。对在高温高湿环境下机器工作时出现的问题作了具体分析，并提出了改进措施。     

ICP—arc粉末法同时测定有机物中微量元素

ICP光源已广泛和成功地应用于溶液样品的分析。由于固体样品的溶解处理麻烦,溶液进样技术又存在着易沾污和样品被稀释等局限性,所以本实验室致力于固体粉末直接进样法研究,设计了粉末进作器和封闭式ICP-arc加长炬管系统,简称ICP-arc。利用这些装置,可使     

稀土对激光重熔合金化层组织与性能的影响

本文研究了加稀土与不加稀土的FeBSi非晶粉末涂层经激光重熔后的组织与性能。结果发现,两者相比,前者合金化层的硬度和耐磨性均比后者提高一倍左右。显微组织分析表明,加入稀土的激光重熔合金化层有马氏体相变发生,其组织为奥氏体及部分马氏体枝晶,碳化物、合金化合物与奥氏体及马氏体枝晶,碳化物、合金化合物与奥氏体及马氏体共晶组成。层内晶粒细小,共晶化合物多,形态规整、分布均匀。未加稀土的激光重熔合金化层中没有马氏体相变发生,其组织为奥氏体枝晶和枝晶间的枝杈状、锯齿状碳化物和合金化合物等共晶组成,层内晶粒粗大,共晶化合物大小不等且分布不均。     

超细羽绒粉体/天然橡胶共混膜的制备及力学性能研究

采用γ-巯基丙基三甲氧基硅烷(KH590)、苯基异氰酸酯(PI)和十八烷基异氰酸酯(ODI)对超细羽绒粉体进行表面疏水化改性,制备了不同羽绒粉体含量的超细羽绒粉体/天然橡胶弹性体共混膜.分析了粉体含量及不同改性剂对天然橡胶共混膜吸水性能和拉伸力学性能的影响.结果表明:粉体的添加提高了共混膜的吸水率,与未改性粉体相比,PI和0DI对粉体改性可降低共混膜的吸水率,并提高了共混膜的断裂强度和断裂伸长率.共混膜的弹性模量随粉体含量的影响较大.     

Deformation mechanism and quantitative characterization of Al2O3 inclusions in powder metallurgy superalloys

By means of implanting inclusions artificially, the evolution law of three-dimensional morphology and size of Al₂O₃ inclusions in FGH96 powder metallurgy (PM) superalloy during hot iso-static pressing (HIP), hot extrusion (HEX) and hot isothermal forging (HIF) process was investigated by SEM and quasi in situ Micronano-CT. The size change of inclusions during different stages was studied quantitatively, the three-dimensional (3D) morphology of the inclusions was characterized, and the deformation mechanism was proposed. The results showed that the inclusions in powder stage were long stripe or plate-like shape. During HIP, Al₂O₃ inclusions were mechanically bonded to the alloy matrix, and its chemical composition, morphology and size remained unchanged. During HEX, Al₂O₃ inclusions were broken and elongated into chain shape due to shear stress. The quantitative relationship between inclusion size after extrusion and extrusion ratio as well as original inclusion size was established. During HIF, the relationship between 3D morphology, size, orientation and deformation of a single inclusion during forging compression was quantitatively characterized by quasi in-situ micronano-CT for the first time. The above evolution law provides theoretical basis and technical support for improving the purity level of powder turbine disk.     

基于神经网络的电站仿真器建模方法及应用

本文将神经网络理论应用到电站系统仿真实践中，有效地解决了电站系统仿真研究常遇到的机理复杂的非线性环节的建模问题，并以制粉系统为例，提出了作用函数Φ（ｘ），学习效率系数α的选取方法以及权值Ｗｉ，ｊ的初值设定及要求，给出了提高逼近精度的方法。     

Application Research on Powder Mixed EDM in Rough Machining

Powder Mixed Electric Discharge Machining (PMEDM) has different mechanism from conventional EDM, which can improve the surface roughness and surface quality distinctly and to obtain nearly mirror surface effects. It is a useful finish machining method and is researched and applied by many countries. However there are little research on rough machining of PMEDM. Experiments show that PMEDM machining makes discharge breakdown easier, enlarges the discharge gaps and widens discharge passage, and at last form...