电、磁场对金属凝固组织的影响及应用

利用外加物理场凝固细晶技术是目前材料加工领域的研究热点。综述了各种电、磁场对金属凝固组织的影响，并对其主要的机理进行了探讨；并对电、磁场在金属凝固成形中的应用和进一步研究进行了展望。     

Fabrication of composite wire of lead coated on glass fiber by extrusion

1　INTRODUCTIONCoatingglassfiberwithleadproducesakindofnewcontinuouscomposite ,whichcanfindwideap plicationsinmanydifferentfields ,especiallyinthebatteryoftheEVsandHEVsthathasalreadybecomethemostimportantgoalinmostcountries[13] .Withakindofspecialtechnologythiskindofnewcompos itewirecanbeusedtoproducegridsofnewleadacidbatterythatisveryusefultotheEVsandHEVs .Thiskindofnewleadacidbatteryhasmanyadvan tages ,suchashigherspecificenergy ,lessinnerresis tance ,morequicklychargingcapabilityand…     

冷却强度及变形程度对挤压AZ31镁合金组织性能的影响

选择AZ31镁合金为原材料,在400℃下挤压散热片型材,就冷却强度及变形程度对制品的性能(抗拉强度和导电率)及组织结构的影响进行研究。结果显示:挤压温度为400℃,制品经水冷却,变形程度大的型材具有更高的抗拉强度和导电率。     

Electric and mechanical performances of Bi0.5Sb1.5Te3 prepared by spark plasma sintering

Thermoelectric (TE) materials are a kind of functional materials which can be used to convert directly heat energy to electricity or reversely.The thermoelectric effects hold great potential for application in power generation and refrigeration.Bi2Te3 and its alloys are well known as best TE materials currently available near room temperature.This paper studies respectively the effects of spark plasma sintering (SPS) on electric performance of Bi0.5Sb1.5Te3 thermoelectric materials that are prepared through vacuum melting and ball milling.Through X-ray Diffraction and cold field emission scanning electric microscope s4800, the phase constituent and microstructure of the TE materials samples were analyzed.Electric conductivity and power factor can be improved with the rise of Spark Plasma Sintering temperature (from 300 to 500 ℃) and pressure(from 30 to 60 MPa), and the density and mechanical strength of Bi0.5Sb1.5Te3 thermoelectric material increase, too.     

高密度脉冲电流对A356铝合金凝固组织的影响

研究了高密度脉冲电流对A356铝合金凝固组织的影响，实验中对液相线以下溶体的凝固过程在不同阶段进行电脉冲处理。对比实验结果表明：经过电脉冲处理后，A356的合金凝固组织得到明显细化；在同样的电脉冲条件下，凝固组织细化效果与电脉冲放电开始时间有关，凝固过程中放电开始时间越早，凝固组织细化效果越明显；反之，凝固组织细化效果较差；同时，脉冲充电电压越高，凝固组织细化程度越大。定量计算了脉冲电流产生的电磁力并分析了脉冲电流影响凝固组织的作用机制。     

3300mm轧机辊缝位置控制系统的研制

介绍3300mm中厚板可逆热轧机辊缝调整机构的组成,设计了3300mm轧机辊缝位置控制系统控制方案,给出了该方案中压下电机调速系统的设计过程,最终依据设计方案研制了辊缝控制系统,并在实际生产中运行使用。现场运行结果表明,用有准备切换逻辑无环流控制系统控制压下电机的辊缝位置,性能稳定,定位迅速,控制精度达到±0.3mm。宝钛集团使用该设备生产的钛及钛合金中厚板、镍板、锆及锆合金板等质量达到国际同类产品的先进水平。     

Influences of dehydrating process on properties of ATO nano-powders

1　INTRODUCTIONCrystallineSbdopedtinoxide (ATO) ,cassiteritestructure ,isawidebandgapn typesemiconductor.Be causeofitsopticalproperty (transparentforvisiblelightandreflectiveforIR )andelectroconductibility ,goodchemicalandmechanicalstability ,ithasmanyapplica tions,suchastransparentconductiveelectrodes ,photo voltaicdevices ,photosensors ,catalyst,antistaticcoatingsandelectrochromicmaterials[14 ] .AvarietyoftechniqueshavebeenusedtoprepareATOsuperfinepowders ,someinvolvedryprocesses ,ot…     

电火花加工与加工中心的集成

提出了一种新的复合型机床——在加工中心上进行电火花加工的机床，研究了电火花加工与加工中心集成所存在的主要技术要求，提出并设计了伺服控制系统，介绍了伺服控制系统的原理。为验证这个想法的合理性，在普通的铣床上进行了模拟集成试验并进行了分析与评价。     

Effect of cobalt oxide on surface structure of alumina supported molybdena catalysts studied by in situ Raman spectroscopy

A set of Co promoted 10% Mo/Al₂O₃ samples have been characterized by means of Raman spectroscopy under ambient as well as in situ dehydrated conditions. Under ambient conditions, the degree of the polymerization of surface molybdenum oxide species decreases with increasing Co loading. Under dehydrated conditions, the polymeric molybdenum oxide species is absent with the addition of only 0.2% Co. At low Co loadings (2%), before the formation of CoMoO₄ compound, the spectral features are very similar under ambient conditions. Dehydration causes the upward shift of the Mo=O symmetric stretching mode. A broad band around 920–930 cm^–1 was thus observed. This band has been suggested to be associated with the Co-Mo interaction species. In contrast to crystalline CoMoO₄, this species shows a reversibility on H₂ reduction-O₂ reoxidation treatments. From the results obtained, it is proposed that cobalt oxide interacts with the most polymerized molybdenum oxide species to form Co-Mo interaction species and/or crystalline CoMoO₄; therefore, the amount of the surface molybdenum oxide species decreases with a change in the molecular structure as a function of the Co concentration.     

电除尘器绝缘子的设计与选择

根据电除尘器绝缘子的功能、工况条件等特点，分别从材质、外形尺寸等方面介绍了设计和选择的注意事项。为用户合理地选择电除尘器绝缘子提供了帮助。