盐酸循环浸出强化钼酸钙焙砂分解及资源化回收钙

建立298 K下CaMoO4?CaSO4?H2SO4?H2O,CaMoO4?HCl?H2O和CaSO4?CaCl2?HCl?H2O体系的热力学平衡图.计算结果表明,硫酸钙在盐酸中的溶解度远大于在硫酸中的溶解度.从微观颗粒性质变化的角度探讨钼酸钙焙砂中钼的浸出机理.研究发现,盐酸对钼酸钙焙砂中的钼具有良好的浸出效果,这是...     

CaSO4/HA复合陶瓷制备条件对降解的影响

使用共沉淀法制备了CaSO4/HA复合陶瓷,改变试剂的初始用量和反应条件对复合陶瓷中CaSO4和HA结晶形态和物相组成进行控制.使用Tris模拟体液对CaSO4/HA复合陶瓷进行降解实验.使用SEM对CaSO4/HA复合陶瓷降解前后的断面形貌进行分析.实验结果表明,制备条件对CaSO4/HA复合陶瓷的降解有很大影响,可以通过控制制备条件而达到对HA成孔的设计.     

工艺参数对直流电沉积纳米晶Ni-Fe合金箔的影响

采用直流电沉积的方法在氯化物-硫酸盐体系中制备纳米晶Ni-Fe合金箔,研究了不同质量浓度硫酸亚铁、硼酸、NaCl、十二烷基硫酸钠、糖精、1,4-丁炔二醇、柠檬酸钠对镀层含铁量的影响,采用SEM、XRD、EDS分析Ni-Fe合金箔的形貌、结构和成分.结果表明:体系中组分含量对镀层含铁量有较大的影响;Ni-Fe合金箔表面光滑平整,镀层质量较好,为纳米晶态结构.     

丝粉同步送进激光沉积制备铝基复合材料的显微组织

采用旁轴送进铝丝结合同轴送给WC陶瓷粉末的工艺,在铝基体表面进行激光沉积,以获得铝合金表面的复合材料层。通过优化工艺参数,得到较好的表面沉积层。采用XRD、SEM、EDAX等方法对沉积层进行显微组织分析。结果表明:沉积层中WC陶瓷颗粒在铝基体中发生溶解,在WC陶瓷颗粒周围生成大量杆状和簇状的Al4W、细小颗粒状的W2C以及针状的Al4C3。与基体相比,激光沉积复合材料层的硬度明显提高。     

非贵金属活化氧化铝陶瓷基板化学镀铜研究

提出一种新型的非贵金属活化法辅助二次化学镀的氧化铝陶瓷基板化学镀铜工艺,成功制备了表面完整、分布均匀的铜镀层,进一步通过冷场发射扫描电镜(FE-SEM)做了具体分析。可以发现,经预处理活化之后的氧化铝基板表面产生一定程度的表面缺陷,主要包括不同梯度的台阶,颗粒与颗粒之间的边缘化以及‘地道式’的孔洞。在第一次化学镀铜沉积一定量的铜颗粒之后表面仍存在大量的空隙,即未镀区域。但在二次化学镀工艺之后,表面完全覆盖镀层,其中镀层表面上小的圆球状(2~3μm)铜颗粒夹杂在大的胞状(4~5μm)颗粒之间,整体上为颗粒与颗粒的物理聚集然后通过堆垛而形成的。     

Ti-6Al-4V基体激光植入ZrO2颗粒工艺过程数值分析

为了提高Ti-6Al-4V合金零部件的表面强度及耐热性能,在利用激光熔化后的Ti-6Al-4V材料表面上植入ZrO2陶瓷颗粒。本文基于CFD计算方法建立了三维瞬态激光植入工艺过程数值分析模型并对部分实验结果进行了验证。该模型根据等效热效应对移动激光热源进行计算,利用VOF方法追踪流体的自由表面。考虑浮力、惯性力、粘性阻力对颗粒运动的影响分析了颗粒在熔池内的运动过程,对比分析了是否添加颗粒两种工况下熔池内的温度场与流场分布。结果表明颗粒的进入使得熔池内温度场与流场重新分布,流体的流动和熔池的凝固使颗粒分布于不同位置。通过对100μm深度上熔池不同位置处的颗粒数进行统计发现,随着激光扫描速率的增加,颗粒在基板上表面的分布更加密集。     

Ti-6Al-4V基体激光植入ZrO_2颗粒工艺过程数值分析（英文）

为了提高Ti-6Al-4V合金零部件的表面强度及耐热性能,在利用激光熔化后的Ti-6Al-4V材料表面上植入ZrO_2陶瓷颗粒。基于CFD计算方法建立了三维瞬态激光植入工艺过程数值分析模型并对部分实验结果进行了验证。该模型根据等效热效应对移动激光热源进行计算,利用VOF方法追踪流体的自由表面。考虑浮力、惯性力、粘性阻力对颗粒运动的影响分析了颗粒在熔池内的运动过程,对比分析了是否添加颗粒2种工况下熔池内的温度场与流场分布。结果表明,颗粒的进入使得熔池内温度场与流场重新分布,流体的流动和熔池的凝固使颗粒分布于不同位置。通过对每100μm深度上熔池不同位置处的颗粒数进行统计发现,熔池中颗粒数从表面到底部先增加后减小。随着激光扫描速率的增加,颗粒最密集位置越来越靠近熔池表面。     

化学涂层对玻璃表面与微颗粒耦合规律的影响(英文)

通过玻璃表面的试剂涂层与空气中微颗粒的耦合性实验发现,试剂涂层能明显改变表面与微颗粒的耦合能力,微颗粒平均粒径与采样的时间间隔、放置夹角和试剂浓度没有明显规律性联系,复合试剂耦合微颗粒的粒径比单一试剂的粒径小(2~3μm),其中吐温60粘附微颗粒的粒径最大(4~5μm),0.5%SDBS与0.5%氟碳复合试剂涂层表面粘附微颗粒数量的能力最强。每种试剂对微颗粒的粘附强度存在一个最佳范围。研究发现,复合试剂能获得单一试剂不具备的特殊物理化学性质,能有效改变固体表面与微颗粒的耦合性质。     

Zn基合金中CuZn4化合物在SiC颗粒上的形成机理

通过高分辨透射电镜和带能谱透射电镜观察, 经选区电子衍射和微区化学成分分析, 发现在ZnAl27复合材料中, SiC颗粒周边存在着大量的CuZn4化合物. CuZn4依附于SiC颗粒形核, 其沿SiC晶面长大速率大于垂直方向的长大速率.     

电沉积制备纳米晶铁-镍-铬合金箔工艺及机理研究

以复合羧酸为配位剂,在含三价铬离子的水溶液中,电沉积制备Fe-Ni-Cr合金箔,研究铬盐浓度、电流密度和供电方式等对箔成分和成箔性能的影响,采用SEM、TEM、XRD和EDS对合金箔进行表征,对合金箔的力学、电和耐蚀性能进行研究,并研究合金箔沉积机理。结果表明,采用复合羧酸体系脉冲电沉积可制备出Cr的质量分数为5%~8%的高Cr光滑合金箔,其微观形貌为紧密堆砌的球状颗粒,晶粒尺寸10nm以内,主相为Cr与α-Fe或γ-Fe形成的固溶体。合金箔中Cr含量提高,箔的电阻率、硬度和耐蚀性也随之升高。Fe-Ni-Cr合金共沉积为电化学控制,由于Cr3+加入,合金沉积阻力加大,速度降低。     

激光送粉增材制造光粉交互作用机制分析

激光同轴送粉增材制造过程中，粉末粒子和激光束发生能量交互作用的剧烈程度决定了粉末粒子进入熔池前存在的状态.借助背影增效瞬态影像捕捉方法及图像信息处理技术，从宏观和微观角度研究了激光辐照下粉末束流及粒子的变化特征.提取高亮状态粒子数量、亮区总面积和单个粒子亮区面积均值作为特征参量，综合表征工艺参数对该过程的影响规律.结果表明，通过主要工艺参数的合理匹配可以很好的实现对光粉相互作用过程的调控.激光能量密度越高，光粉作用时间越长，粉末粒子接受激光辐照的程度就越激烈，以熔融态进入熔池的可能性就越大.     

Effect of microstructure on specific capacitance of AA3003 aluminum alloy foils

1　INTRODUCTIONInrecent years ,highspecificcapacitancehascometobepursuedforsmallelectrolyticcapacitors .Themicrostructuresofthealuminumfoilwillinflu encethespecificcapacitanceofthecapacitorsserious ly .AA30 0 3aluminiumalloyisoftenusedforthecathodeofthecapacitors[17] ,containingMn ,Cu ,Mg ,SiandFe ,andshowinganexcellentcorrosionresistance .ThesolubilityofMninAlmatrixisverylowatroomtemperature ,andMnisoftenprecipitat edintheformofMnAl6 .ThesolubleironinAlma trixisverylimited ,oftenpre…     

厚膜金导体浆料

概括介绍了厚膜金导体浆料。通过改变金粉、粘结剂和有机载体等主要组份的类型和含量,可以制得多种金浆料。①粘结剂类型对厚膜金导体的性能有较大的影响。根据附着机理分类,厚膜金导体分为4种主要类型,即玻璃结合型、反应结合型、混合结合型和表面活化结合型。②金粉颗粒的均匀性、单分散性、表面形态及尺寸对浆料的印刷性能和烧结性能影响大。颗粒表面越光滑,对提高印刷性能越有利。光滑的表面吸附有机载体较少,可减少导体膜在烘干－烧结时的收缩率。③有机载体的含量和流变学性能影响金浆料的印刷性能及烘干－烧结时的收缩率。④金浆中添加起合金化作用的元素,可提高导体在铝丝键合体系及Pb-In焊接体系的热老化性能。⑤为适应新的厚膜工艺技术的需要,研制可光刻的厚膜金导体浆料和金的金属有机浆料[Au MOC]。     

锂电池中铝箔表面形貌对电池性能的影响

10～20μm厚的铝箔经常应用于锂电池的阴极。将被化学腐蚀的粗糙表面铝箔与光滑平面的铝箔进行对比,以考察铝箔的表面形貌对锂电池的影响。对于高电导率且颗粒较大的LiCoO2锂电池材料,两种铝箔的锂电池性能没有明显不同。但是对于低电导率且颗粒较小的LiFePO4材料,高倍率放电性有很大的差异。通过优化铝箔的表面形貌及电池材料的颗粒尺寸,可使电池的性能得到提高。     

Size effects on springback behavior of H80 foils

Size effects make traditional bending theories infeasible in analyzing the springback behavior of H80 foils in the similarity bending experiment. It is observed that there is a certain critical thickness value, which divides the change trend of springback amount of foils into two opposite parts. In order to reveal the reason for size effects on the springback behavior of H80 foils, the method of hardness increment characterization was applied to describe the deformation distribution of foils. The competition between strengthening effect of geometrically necessary dislocations and weakening effect of surface grains determines the change trend of springback amount with foil thickness. When the thickness of foils is large, the weakening effects dominate the material behavior, resulting in that the springback amount decreases with the decrease in foil thickness. However, when the foil thickness is small, the strengthening effects dominate the springback tendency, leading to a sharp increase in the springback amount. Furthermore, the deformation distribution is disturbed due to the enhanced effects of individual grain heterogeneity with the decrease in the thickness of foils, leading to the large scatter of springback angle after unloading.     

Multilayer aluminum composites prepared by rolling of pure and anodized aluminum foils

Experimental results on processing, structural and mechanical characterization of a multilayer composite based on commercially pure aluminum foils were presented. A multilayer composite was produced by hot-rolling of anodized and non-anodized aluminum foils alternately sandwiched. In addition, the same process was applied for bonding of non-anodized foils. In both cases, obtained multilayer composites were compact and sound. In order to study composites microstructural evolution and mechanical properties, optical and scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), X-ray diffraction (XRD) analysis, hardness, tensile and three-point flexural tests were performed. Microstructural characterization confirmed that the rod-like particles distributed in parallel rows in the composite aluminum matrix with anodized foils correspond to Al₂O₃. Maximum and minimum peaks of oxygen and aluminum, respectively, suggest that after the final hot-rolling of composite with non-anodized foils, a small amount of coarser particles were formed at boundaries between foils. Hardness, strength, modulus of elasticity and flexural strength of both multilayer composites were much higher than those of pure aluminum, whereas ductility was significantly less. The composite with anodized foils exhibited the highest strength and modulus of elasticity, but lower ductility compared to composite processed from non-anodized foils. Fracture failure corresponded to the change of ductility.     

Structure and microhardness of rapidly solidified foils of binary indium alloys

Structure of indium and binary indium-based alloys obtained by rapid solidification has been investigated. In the rapidly solidified foils of indium and its binary alloys with tin, lead, bismuth, zinc, and antimony (to 0.6 at %), there is formed a (101) texture, and in the alloys that contain a higher concentration of antimony, an (001) texture. The foils of the alloys that contain to 4 at % bismuth, lead, and cadmium and to 8 at % tin are single-phase. In the foils of the alloys containing zinc and antimony, dispersed particles of zinc and indium antimonide are precipitated.     

Effect of Y on Microstructure and Mechanical Properties as well as Corrosion Resistance of Mg-9Li-3Al Alloy

利用二次离子质谱仪对高压电解电容器用高纯铝箔的微量元素进行了分析,研究了微量元素含量及分布对铝箔织构及性能的影响.结果表明:铝箔中Fe、Si、Cu和Pb含量较高,Fe、Cu元素含量直接影响铝箔的电性能,而Si和Pb元素含量的变化,对铝箔的织构和电性能无直接影响.铝箔中微量元素的平均含量,是影响铝箔织构组成与最终电性能的主要因素.而Fe、Cu等微量元素在近表面深度方向上浓度梯度方向的改变和显著波动,可导致在腐蚀发孔过程中微量元素的微观作用机制发生改变,不利于隧道孔的稳定生长,也是影响铝箔最终电性能的又一个重要原因.     

Growing and stability of gold nanoparticles and their functionalization by cysteine

Gold nanoparticles in aqueous dispersion were prepared using the trisodium citrate reduction method to control the size of particles by changing the concentration of HAuCl₄. The average particle size measured by DLS is higher than that obtained by TEM at a zeta potential of -40 mV. When trisodium citrate concentration is kept constant, the particle size increases with gold concentration. The kinetics of growth was studied and apparent kinetic rate constants were determined at various gold/citrate ratios. Gold nanoparticles were attached to silanized glass surfaces; Au rods were grown (ca. 200 nm) by adding more precursors and the rods’ growth rate was monitored by UV-Vis spectroscopy as well as by AFM. Surface functionalization of gold surface was influenced by cysteine. The surface modification by cysteine at pH=6.0 results in aggregation and the red shift of absorption maximum is nearly 200 nm. When glutathione molecules are bound onto the cysteinelinked Au rods on the glass surface, the spectral shift reaches only an amount of 5–10 nm, because the surface attachment hinders the tendency to aggregate.     

Preparation of novel core-shell nanoparticles by electrochemical synthesis

Nanostructural gold/polyaniline core/shell composite particles on conducting electrode ITO were successfully prepared via electrochemical polymerization of aniline based on 4-aminothiophenol （4-ATP） capped Au nanoparticles. The new approach to the fabrication included three steps： preparation of gold nanoparticles as core by pulse electrodeposition; formation of ATP monolayer on the gold particle surface, which served as a binder and an initiator; polymerization of aniline monomer initiated by ATP molecules under controlled voltage lower than the voltammetric threshold of aniline polymerization, which assured the formation of polyaniline shell film occurred on gold particles selectively Topographic images were also studied by AFM, which indicated the diameter of gold nanoparticles were around 250 run. Coulometry characterization confirmed the shell thickness of polyaniline film was about 30 nm A possible formation mechanism of the Au/polyaniline core-shell nanocomposites was also proposed. The novel as-prepared core-shell nanoparticles have potential application in constructing biosensor when bioactive enzymes are absorbed or embedded in polyaniline shell film.