超细硬质合金钴相分布均匀性对PCB铣刀使用性能的影响

将钴质量分数为6%的3种钴相均匀性不同的超细硬质合金棒材制成PCB铣刀,对3种超细硬质合金棒材及PCB铣刀样品进行物理力学性能、显微组织结构和铣刀使用性能的对比,使用ICALIBUR钴相分析软件定量分析硬质合金棒材钴相分布均匀性,研究钴相分布均匀性对PCB铣刀使用性能的影响。结果表明:钴相分布均匀性在物理力学性能上没有体现,只能通过直接的钴相分布检测方法进行检测,钴相分析软件检测显示,钴相质量分数在5%~7%的微区间,样A为50%,样B为66%,样C为80%。制成PCB铣刀后,钴相均匀性较差的样A、样B比钴相均匀性较好的样C寿命低20%以上。钴相分布均匀性差会造成硬质合金棒材制成的铣刀刃局部区域的硬度不均匀,使得铣刀在使用过程中产生磨损不均匀和崩缺现象,导致使用寿命降低。

硅胶担载的钴膦配合物催化剂中钴含量的分析方法

硅胶担载的钻膦配合物经矿化之后,钴样在PH=4—7的介质中与4—[(5—chloro—2—pyridyl)azo]—1,3—diaminobenzene生成一种红色配合物,该配合物在酸性介质中颜色加深,利用分光光度法测定钴含量.

一种智能型钴自动分析仪的研制

系统地介绍了一种用于溶液中钴含量测定的智能型自动分析仪器 ,其化学分析依据工业上常用的钴的国标分析法—亚硝基R盐光度法 .通过机械传动部分和单片机系统将整个分析过程智能化、自动化 ,从采样到信号处理和结果输出均为自动完成 ,并且提供分析过程中参数的可调功能 ,整机采用梯形构架 。

钴酸锂原材料四氧化三钴中亚钴的X射线衍射定量分析

X射线衍射技术是研究物质晶体结构及其变化规律的主要手段,是材料结构表征技术的重要组成部分。随着实验技术的发展,X射线衍射应用越来越宽,且基于物质结构深度研究的功能也越来越强大。粉末衍射的基本应用是根据衍射峰位置和衍射峰强度建立起来的物相定性和定量分析。本文主要开发了用X射线衍射测定四氧化三钴中亚钴含量的方法,介绍了定量分析的原理及对实验条件的选择,结果表明,此方法可以作为对钴酸锂原材料质量评判的标准。

分光光度法测定钢铁中钴

分光光度法测定钢铁中钴王怀生，崔慧，张国荣（山东省聊城师范学院化学系，聊城，２５２０５９）由于Ｃｏ２＋与ＳＣＮ－形成的络合物稳定性较差，所以在水相不显色，通常是将Ｃｏ２＋与ＳＣＮ－形成的络合物用有机溶剂萃取后测定［１］，或者将Ｃｏ２＋与ＳＣＮ－形成的...

原子吸收法测定土壤中钴时的背景干扰及消除

本文利用国家一级标样中钴的推荐值与该标样多次测定平均值的比值、并对不同基体成分进行比较试验求得消除背景的校正系数将此系数代入分析结果计算公式，即可消除背景干扰，获得比较准确的分析结果。结果表明，本法的准确度，精密度均较好，可满足土壤中钴的测定要求。

原子吸收分光光度法测定触媒合金中的钴

介绍了用原子吸收分光光度法测定触媒合金中的钴，其结果与标准值一致。

亚硝基R盐吸光光度法测定钴含量时不同价态铁元素对结果产生干扰的研究

亚硝基R盐吸光光度法测定高温合金中钴含量极为常见,而在试验中其它常见元素也容易对实验结果产生干扰,本文针对铁元素以及铁的两种常见价态分别研究。选取不含铁元素的标准,于发色前分别加入相应研究对象,在相同的操作规程下通过测量结果相互比较,最后得出结论。如果存在干扰,那么和干扰元素含量多少有何关系。对通过加入掩蔽剂方法能否达到理想效果以及最佳显色条件分别探讨。

Thermodynamic analysis on synthesis of fibrous Ni-Co alloys precursor and Ni/Co ratio control

According to the principles of simultaneous equilibrium and mass equilibrium, a series of thermodynamic equilibrium equations in Ni（II）-Co（II）-C2O4^2--NH3-NH4^＋-H2O system at ambient temperature were deduced. The diagrams of logarithm ion concentrations versus pH values at different solution compositions were drawn. The results show that Ni^2＋ and Co^2＋ can completely precipitate at pH less than 5.0 and the predefined Ni/Co ratios can be well kept in the precursor. The precursor morphology is granular aggregation. However, rod aggregation precursor is obtained in the pH range of 5.0-8.0, and fibre-shape precursor is got at pH value higher than 8.0. The Ni/Co ratios in the above two precursors are not reproduced as that in the feed due to the formhtion of multi-coordinated Ni（NH3）n^2＋ and Co（NH3）n^2＋ （n=1-6）. Modification of precipitation medium is favorable for the precursors to keep the predefined Ni/Co ratios of the feed in the pH range of 2.0-8.6. Meanwhile, the precursors with fibrous morphology can be obtained.

Cobalt recovery and microspherical cobalt tetroxide preparation from ammonia leaching solution of spent lithium-ion batteries

A process for recovering Co and preparing microspherical Co_(3)O_(4)through NH_(3)distillation and phase transformation from ammoniacal solution was investigated.As the basis of thermodynamics,the solubility of Co at different NH_(3)and CO_(3)^(2-)concentrations was studied,and then the effects of different NH_(3)distillation conditions on Co recovery rate were discussed.Over 94%Co and 96%NH_(3)were recovered through NH_(3)distillation,and the cobalt was precipitated in form of cobalt carbonate ammonium compound salt.Through the analysis of the formation mechanism of the precursor,the precipitation process of cobalt could be divided into two stages,and the cobalt precipitation rate was significantly accelerated in the second stage.In phase transformation,the effect of temperature on the roasted product was investigated.The microspherical Co_(3)O_(4)with a microporous structure was prepared at 300°C,and Co_(3)O_(4)with a mesoporous structure and high-spin state was obtained at 750°C.

Solvothermal synthesis of nanosized CoSb_3 skutterudite

Nanostructures enhance phonon scattering and improve the figure of merit of thermoelectric materials. Nanosized CoSb3 skutterudite was synthesized by solvothermal methods using CoCl2 and SbCl3 as the precursors. A 'two-step' model was suggested for the formation of CoSb3 based on the X-ray diffraction analysis. The first step is the formation of cobalt diantimonide in the earlier stage during the synthesis process. Diantimonide was then combined with antimony atoms to form the skutterudite structured triantimonide, CoSb3, in the later stage of the synthesis process as the second step. The synthesized CoSb3 powders consist of irregular particles with sizes of about 20 nm and sheets of about 80nm.

Influence of Chemical Effect on the Kβ/Kα Intensity Ratios and Kβ Energy Shift of Co, Ni, Cu, and Zn Complexes

Chemical effects on the Kβ/Kα intensity ratios and △E energy differences for Co, Ni, Cu, and Zn complexes were investigated. The samples were excited by 59.5 keV γ-rays from a ^241Am annular radioactive source. K X-rays emitted by samples were counted by an Ultra-LEGe detector with a resolution of 150 eV at 5.9 keV. We observed the effects of different ligands on the Kβ/Kα intensity ratios and △E energy differences for Co, Ni, Cu, and Zn complexes. We tried to investigate chemical effects on central atoms using the behaviors of different ligands in these complexes. The experimental values of Kβ/Kα were compared with the theoretical and other experimental values of pure Co, Ni, Cu, and Zn.

F^2∑^＋-X^2∑^＋ Band System of Cobalt Carbide

The laser-induced fluorescence excitation spectrum of CoC was recorded in the spectral region from 13500 cm^-1 to 22000 cm^-1, in which the CoC molecules were produced by the reaction of sputtered cobalt atoms with methanol under supersonic jet cooled conditions. Much of the visible spectrum was assigned to transitions between the X2∑^＋ ground state and F2∑^＋ state. The 11 bands assigned as （v＇=3-13, 0） transitions of the F^2∑^＋-X^2∑^＋ band system were observed and rotationally analyzed. Equilibrium constants for the F^2∑^＋ state were Te=13628 cm^-1, We=669 cm^-1, ωeХe=4.3 cm^-1, Be=0.546 cm^-1, and Re=1.758A. Some new bands were observed.

Electrocatalytic hydrogen evolution from water at low overpotentials with cobalt complexes supported by redox-active bipyridyl-NHC donors

Three cobalt complexes bearing tunable,redox-active bipyridyl N-heterocyclic carbene(NHC)-based ligands have been studied for electrocatalytic hydrogen evolution from aqueous solutions.The effect of structural modifications to the ligand framework is investigated across the catalyst series,which includes a non-macrocyclic derivative(1-Co)and 16-(2-Co)and 15-(3-Co)membered macrocycles.A structure-activity relationship is demonstrated,in which the macrocyclic complexes have greater activity compared to their non-macrocyclic counterpart with the most rigid catalyst,supported by the 15-membered macrocycle,performing best overall.Indeed,3-Co catalyzes H2 evolution from aqueous pH 4 acetate buffer with a Faradaic efficiency of 97%at a low overpotential of 330 mV.Mechanistic studies are consistent with formation of a cobalt-hydride species that is subsequently protonated to evolve H2 via a heterolytic pathway.

FEM analysis on the effect of cobalt content on thermal residual stress in polycrystalline diamond compact(PDC)

Thermal residual stress in Polycrystalline Diamond Compacts （PDCs） is mainly caused by the mismatch in the Coefficients of Thermal Expansion （CTE） between the polycrystalline diamond （PCD） layer and WC-Co substrate. In the PCD layer, the CTE of cobalt exhibit magnitudes four times larger than those of diamond. Cobalt content in the PCD layer has important effects on the thermal residual stress of PDCs. In this work, the effects of cobalt content on thermal residual stress in PCDs were investi- gated by the Finite Element Method （FEM）. The simulation results show that the thermal residual stress decreases firstly, and then increases with increasing cobalt content （1 vo1.%-20 vol.%）, which reaches a minimum value when the cobalt content is about 10 vol.%. The FEM analysis results are in agreement with our experimental results. It will provide an effective method for further designing and optimizing PDC properties.

Effect of Cobalt-Doped Framework on Formation of Todorokite from Layered Manganese Oxides with Mg^(2+)/Co^(2+) Ions as Template

Cobalt （Co） exists in significant quantities in naturally occurring manganese （Mn） oxides and alters the growth of Mn oxide crystals. Four-layered Mn oxides, Na-buserite （Na-bus） and three Co-doped Na-buserite samples prepared from oxidation of Mn（OH）2 with 5%, 10%, and 20% Co/（Mn ＋ Co） molar ratios （5Co-Na-bus, 10Co-Na-bus, and 20Co-Na-bus）, were used to prepare todorokite, a common Mn oxide on the Earth＇s surface, using Mg2＋/Co2＋ ions as a template. The results showed that todorokites could be obtained by reflux treatment of Mg2＋-exchanged non-doped Na-buserite and three Co-doped Na-buserites at atmospheric pressure. However, the formation of todorokites was prohibited by reflux treatment of Co2＋-exchanged Na-bus, 5Co-Na-bus, and 10Co-Na-bus samples. Instead, todorokite was obtained by the reflux treatment of Co2＋-exchanged 20Co-Na-bus samples under atmospheric pressure. X-ray photoelectron spectroscopy analysis showed that doped Co existed as Co3＋ in the MnOs layers of doped Na-buserites. The amount of substituted Co3＋ in the MnO6 layers may play a key role in the conversion of buserite to todorokite using Co2＋ ions as a template.