快速凝固Mg94.6Zn4.8Y0.6镁合金薄带的组织与性能

采用单辊快速凝固技术制备了Mg94.6Zn4.8Y0.6合金薄带,研究了薄带的组织及性能特征。结果表明:Mg94.6Zn4.8Y0.6镁合金快速凝固薄带组织由过饱和的单相-αMg固溶体组成,沿厚度方向分为两个晶区:近辊面粗大等轴晶区和自由面细小等轴晶区。Mg94.6Zn4.8Y0.6合金快速凝固薄带的显微硬度为85.95HV,在250℃左右保温2 h的显微硬度最高,超过该温度(250~300℃)显微硬度显著下降。     

Study on sintering process and characteristic of nanosized soft magnetic MnZn ferrite powders

The effect of sintering process (especially the sintering temperature) on the magnetic property and microstructure of sintered sample of nanosized soft magnetic MnZn ferrite powder was investigated. The sintered sample of MnZn ferrite was prepared by both traditional pressing and cool isostatic pressing on MnZn ferrite nanoparticals. The sintering process of which was segmented. Thedensity, microstructure and phase composition of sintered sample were analyzed by Archimedes'law, scanning electron microscopy (SEM) and X-ray diffraction (XRD). The grain growth and densification in sintering process of MnZn ferrite were investigated. The magnetic property was measured by vibrating sample magnetometer (VSM) and Nim2000 magnetic material testing system. The results show that the better sintering temperature is 850 ℃, at which the better magnetic property and microstructure of sintered compact were obtained.     

WD615气缸体铸件材料性能的改善

WD615气缸体铸件曾发生化学成分不稳定、铸件本体组织粗大、铁素体含量偏高、硬度偏低等质量问题，为此，采取了如下措施：1）加强熔炼用材料的质量控制；2）提高冲天炉的熔炼质量；3）改进熔炼工艺（调整C,Si量，采用Cu-Cr-Sn合金化；降低浇注温度）；4）改进孕育工艺；5）采用炉前快速检测技术；6）加强铸件本体质量检测。结果表明，缸体铸件的化学成分、金相组织及力学性能均满足技术要求。     

快速凝固Mg94.6Zn4.8Y0.6合金薄带微观结构及显微偏析

采用单辊快速凝固技术制备了Mg94．6 Zn4．8 Y0.6合金快速凝固薄带，并通过扫描电镜的背散射及线扫描研究了快速凝固Mg94．6 Zn4．8 Y0.6合金薄带的显微偏析。结菜表明，由于溶质截流，单辊快速凝固Mg94．6 Zn4．8 Y0.6合金薄带为过饱和单相α—Mg固溶体的蜂窝状组织，Mg、Zn和Y宏观分布比较均匀。但在薄带厚度方向上存在偏析，在晶内也存在显微偏析，偏析形成是由于从辊面到自由面凝固速度的差异及溶质传输和晶格结构造成的，其中Zn元素偏析最大，Y元素次之，Mg元素最小。     

基于价值链的钢铁企业物料采购策略研究

在价值链中蕴含着很多成本控制机会,价格链分析是制造企业进行成本控制的最有效的途径.文中以价值链的观点分析了某钢铁企业的采购流程,提出了基于价值链的物料采购模型,在此基础上改进了该钢铁企业的管理流程,为钢铁企业节约采购成本提供了指导思想.     

Preparation and properties of nanosize MnZn ferrite from δ-FeOOH

Ferrous ion was transformed into feroxyhyte (δ-FeOOH) by oxidation. Then, manganese sulfate and zinc sulfate in some ratio were added to the feroxyhyte solution. The co-precipitation was boiling reflux conditions sometime under constant stirring. The nanosize MnZn ferrite powder was formed. The mechanism of preparation of the nanosize MnZn ferrite was discussed, and the formation of feroxyhyte which was playing a key role during the process was mentioned. The properties of powder was tested by means of X-ray diffraction, transmission electron microscopy and vibrating sample magnetometer. The results show that the samples of spherical particles about 20 nm, which have characteristics of ferrimagnetism, has larger saturation magnetization, but the remanent magnetization and coercivity are comparatively smaller. The spinel MnZn ferrite nanosize powder was successfully prepared from δ-FeOOH at low temperature, with low-carbon steel and peroxide as main material.     

新型Ag_mCu_nHgI_4可逆热致变色颜料的研究

将Cu(NO3 ) 2 和AgNO3 溶液以不同比例同时加入K2 HgI4水溶液中合成了系列AgmCunHgI4(m +n =2 )可逆热致变色颜料。研究发现 :随着Ag和Cu比例的改变 ,颜料变色温度呈现出一定的变化规律 ;当m和n的比例接近 1∶1时 ,变色温度达到最低 35℃ ;降低环境温度 ,可以缩短产品的复色时间 ;差示扫描量热分析 (DSC)图谱中颜料的相变温度与目测变色温度表现出相同的规律性。在分析AgmCunHgI4颜料变色机理的基础上 ,结合晶体微观结构 ,推测得出晶体的微观对称性越低 ,颜料的变色温度越低的结论     

PVC基阻尼涂料的制备及其流变性能

以聚氯乙烯（PVC）为基体，对苯二甲酸二辛酯（DOTP）为增塑剂，与无机填料CaCO3、钙锌热稳定剂、乳化剂OP-10、润滑剂液体石蜡等复合改性制备PVC基阻尼材料，采用动态流变仪DHR、动态热机械分析仪DMA、扫描电镜SEM等对试样的性能和形态进行表征。运用正交设计探究各组分对性能的影响规律，结果表明，填料CaCO3和增塑剂DOTP比例对其阻尼性能影响最显著；当PVC: CaCO3: DOTP: OP-10比重为45: 33: 22: 2时，25℃时频率0.01～150 Hz范围内，tan δ最大值从0.497提高到0.604；剪切速率0.1 s-1时表观黏度为3738 Pa·s，剪切速率150 s-1时表观黏度为2.19 Pa·s，具有优异的抗流挂性与稳定性。通过LASD形态分析构建微观聚集态模型，提出刚性填料团聚-解团聚和聚合物微球变形对流变性能的作用机理，为LASD的持续研究提供技术思路和理论基础。     

低翘曲玻纤增强PET复合材料的制备和性能研究

依据降低翘曲的机理，选用不同降低翘曲的方法，制备了系列翘曲玻纤增强PET复合材料，结果表明，具有较高形状对称性的填料，如滑石粉，云母粉和玻璃微珠都能不同程度地降低玻纤增强PET体系的翘曲，非晶聚合物也能有效改进该体系的翘曲性能。     

流程生产的可视化整合和多目标优化软件

针对现代企业所面临的挑战，开发了一个软件系统可以根据市场的动态变化和企业内部的设备状况，优化设备配置、优化原料和产品方案。采用可视化形式实施仿真运行和经济效益分析预测。