碳化钨化学腐蚀液组成的研究

碳化钨硬质合金特殊的耐磨性和化学稳定性使得对其的加工条件很苛刻，采用HN03与HF混酸做腐蚀剂，在适宜的腐蚀工艺条件下，能够控制腐蚀速度和材料表面光洁度，可以实现对碳化钨硬质合金的精细加工。     

超细碳化钨粉末的制备研究现状及进展

碳化钨是一种重要的硬质合金材料,也是一种性能优良的催化材料,本文对近年来超细碳化钨粉的制备方法分为气相法,液相法和固相法三大类,并围绕碳化钨的颗粒细化,从钨源和碳源的选择,工艺流程等方面进行了归纳,     

一种纳米级碳化钨粉的制备方法

本发明公开了一种纳米级碳化钨粉[粒度≤0．2μm、w（化合碳）≥6．10％]的制备方法，它是以纳米（粒度≤0．2μm）钨粉、纳米炭黑为原料，将纳米钨粉与纳米炭黑放入容器，并向容器内通入惰性气体，在惰性气体保护状态下将纳米钨粉与纳米炭黑进行搅拌混合，混合过程中加入0．5％～3％的有机活性材料，待混合均匀后，在500～1500kg／cm^2压力下压制成块，煅烧压块（W＋C），使纳米钨粉、纳米炭黑化合形成碳化钨（WC），待碳化钨形成后，采用气流研磨方式将碳化钨研磨、打散形成纳米级碳化钨粉。该方法具有工艺流程短、投资少、产量大、产品质量及稳定性均可得到大幅度提高的特点，是一种环保型的制备方法。     

高比表面积碳化钨制备及其在锂空气电池中电催化性能研究

锂空气电池具有高能量密度和良好的发展前景,但其循环性能仍不能满足使用要求,而空气电极侧(即正极)的电化学反应对电池的循环可逆性具有显著影响,正极催化剂的引入可以显著改善电池的循环性能。以高比表面积的石墨相氮化碳介孔材料作为模板和碳源,以六氯化钨为钨源,通过高温反应制备具有较高比表面积的碳化钨材料,并以该碳化钨作为锂空气电池的正极催化剂。利用透射电子显微镜(TEM)、X射线衍射(XRD)、物理吸附等对合成的样品进行表征,结果表明制备的样品为碳化钨材料,并且具有较高的比表面积。采用电化学测试方法研究了碳化钨材料在锂空气电池中的电催化效果,结果表明该碳化钨材料在锂空气电池中具有良好的电催化性能,电池可以保持较长时间的稳定循环状态。     

俄独特方法生产碳化钨纳米粉简单经济

正俄罗斯托木斯克理工大学开发出一种生产碳化钨和其他超硬材料的独特方法。该方法比同类技术简单、经济、可靠,同时,还能用含有相似材料的废物作为生产原材料。相关研究成果近日发表在《国际难熔金属与硬质材料》期刊上。碳化钨是一种超硬材料,广泛用于生产钻头、刀具和其他耐磨零件。     

四川建全球最大硅微粉基地

四川省新津县近日与香港海贯新材料控股有限公司签定年产3000吨球形硅微粉、年产2000吨碳化钨及年产2000吨碳化钨球化工程项目。项目将投资4000万欧元．在新津工业同区建设全球最大的硅微粉新材料基地。项目建成后．应用于航空航天事业的高科技材料－高质量球形硅微粉和球形碳化钨将不再依赖国外进口．实现自主生产。     

混捏机碳化钨搅刀的补焊修复工艺

介绍了修复混捏机动搅刀表层的一种新型耐磨材料--碳化钨,根据工作实践,主要阐述了使用碳化钨材料进行动搅刀表层补焊修复时的工艺要求及经验总结.     

敷焊碳化钨提高粉碎机鼠笼耐磨性

介绍一种应用碳化钨焊条在鼠笼齿档上进行敷焊的新方法，提高鼠笼式粉碎机鼠笼的耐磨 ，增加提高生产能力，延长使用时间，节约材料费用。     

钨酸三乙醇胺热分解法合成碳化钨陶瓷涂层工艺及其对农药废水的电催化氧化能力初探

提出了一种制备碳化钨陶瓷的新方法-钨酸三乙醇胺浸渍热分解法。研究表明,用该法可成功制得碳化钨涂层材料。经过综合热分析仪的测定可得出,碳化钨生成温度为954.5℃。通过碳化钨的X射线衍射(XRD)分析可知,该工艺合成的碳化钨主要成份为W_2C。将所制备的碳化钨陶瓷作电极电解含甲胺磷的农药废水。实验证明,在电压为30V,电流为0.03A时,随着通电时间的加长,有机磷转化为无机磷的程度随之增大。当电解时间为165min时,有机磷的转化率可达9.8%,高于同等条件下碳电极的1.6%。     

关于粉末冶金中碳化钨粉体颗粒细化

碳化钨是在结构强度上仅仅可以与金刚石相媲美且可大规模工业制造的金属化合物,其大规模使用于工业,军事等装备制造领域。我国碳化钨粉体制备技术水平处于落后状态,致使部分原料、制品依赖进口。本文通过对粉末冶金技术制备粉体的方法进行介绍,对其他金属粉体制备进行展开类比并类比,从而提出对制备碳化钨粉体工艺的相应改进,已达到对现有科技状态下的尽可能的提高碳化钨粉体颗粒的细化,以至于可以应对工业使用标准,尽可能降低国内对进口材料的依赖。     

我国水泥工业金属耐磨材料用量分析

庞大的水泥工业离不开高性能的耐磨材料的支撑.2010年我国水泥产量18.8亿吨,估算消耗了17.86万吨金属耐磨耐热材料,消耗铸球达23.39万吨.分析认为:随着水泥生产工艺技术的进步,水泥工业对金属耐磨材料的消耗有所减少,但对耐磨衬板、高铬铸球、破碎机类耐磨材料仍有较大需求,对堆焊耐磨材料的需求将有所增加.     

A Review on Wearable Electrospun Polymeric Piezoelectric Sensors and Energy Harvesters

In recent years, wearable sensors and energy harvesters have shown great potential for a wide range of applications in personalized healthcare, robotics, and human–machine interfaces. Among different types of materials used in wearable electronics, piezoelectric materials have gained enormous attention due to their exclusive ability to harvest energy from ambient sources. Piezoelectric materials can be utilized as sensing elements in wearable sensors while harvesting biomechanical energy. Electrospun piezoelectric polymer nanofibers are extensively investigated due to their high flexibility, ease of processing, biocompatibility, and higher piezoelectric property (in contrast to their corresponding cast films). However, as compared to piezoceramic materials, they mostly exhibit relatively lower piezoelectric coefficients. Therefore, considerable efforts have been devoted to improving the piezoelectricity of electrospun polymer nanofibers recently, resulting in significant advances. This review presents a broad overview of these advances including new material, structure designs as well as new strategies to enhance piezoelectricity of electrospun polymer nanofibers. The challenges in achieving high mechanical performance as well as high piezoelectricity are particularly discussed. The main motivation of this review is to examine these challenges and highlight effective approaches to achieving high-performance piezoelectric sensors and energy harvesters for wearable technologies.     

Fully biobased epoxy from isosorbide diglycidyl ether cured by biobased curing agents with enhanced properties

This research focuses on fabricating a one-step nano-generator based on electrospun nanofibrous materials for wearable electronics textiles applications. A nanofibrous structure from Poly (vinylidene fluoride), PVDF, was produced using electrospinning technique. Performances of these structures were evaluated by using X-ray diffraction (XRD), Fourier Transform Infrared (FTIR), Differential Scanning Calorimetry (DSC) and Scanning Electron Microscopy (SEM). Piezoelectric properties of fabricated composites also were evaluated on a self-made system as a function of frequency. Results showed that not only electrospinning process can effectively improve piezoelectric properties of nanofiber mats by changing the crystalline structure (e.g. create the β-phase) compared to PVDF film samples, but also the fibrous structure of these materials interestingly can be used in the wearable electronic textiles. By using a novel approach to fabricate the nanofiber layer along with incorporating the electrodes within the structure of the device, the electrical output was improved as high as 1 volt. These results imply promising applications for various wearable self-powered electrical devices and systems.     

One-dimensional electrospun ceramic nanomaterials and their sensing applications

One-dimensional sensing materials that are prepared via electrospinning and controlled annealing exhibit intrinsic properties, such as electron transmissivity, magnetic susceptibility, specific heat capacity, as well as optical and mechanical characteristics. Particularly, the electronic transmission characteristics of the ceramic fiber materials, such as the electrical conductivity, photocurrent, magnetoresistance, nanocontact resistance, and dielectric properties, exhibited great potential for applications in the next generation of electronic sensing devices. First, electrospun ceramic materials with different structural and functional characteristics were reviewed here, after which the strategies for improving their properties, as well as the method for assembling the flexible devices, are summarized. Moreover, the electrospun ceramic nanofibers were detailedly discussed regarding applications in device construction and wearable electronics, such as photosensors, gas sensors, mechanical sensors, and other energy storage devices. Finally, the future development direction of the electrospinning technology for multifunctional and wearable electronics skin was proposed.     

基于镍材料的柔性固态超级电容器研究进展

柔性固态超级电容器在可穿戴电子设备的储能领域发挥着重要作用，电极作为关键部件，决定了储能器件的性能。镍基材料具有优越的电化学性能，作为电极材料具有广阔的应用前景。根据化学成分将镍基材料分为若干类，重点介绍了镍基/金属以及镍基/非金属材料柔性固态超级电容器的最新进展。简要总结了镍基材料面临的挑战，并对未来的发展进行了展望。     

Al2O3-W复合材料的抗渣蚀性能

在埋炭条件下,以金属铝粉、氧化钨及刚玉为原料,对以铝热反应为基础制备的Al2O3-W复合材料的抗渣性能进行了研究.结果表明Al2O3-W复合材料的抗渣性能随金属钨含量的增加而改善.金属钨和渣较差的润湿性是一个重要因素,而氧化铝和熔渣的反应机理和常规刚玉质材料的抗渣蚀机理一致.金属钨和渣中被还原的铁相反应生成高熔点相Fe7W6,增加了液相的粘度,抑制了熔渣的侵蚀和渗透.     

High-throughput data mined prediction of design and preparation of flexible carbon-based conductive materials in energy storage

Carbon-based material have been attracted significant attention and widely studied for its excellent electrical conductivity. The prediction of conductivity of carbon-based materials is indispensable to designing and fabricating flexible carbon conductive materials in smart wearable before experimentation. To achieve this objective, ensemble data mining is utilized to automatically search for relationship between factors (filler type, output conductivity, filling fraction, drying temperature, molding temperature, sample thickness, ultrasonic treatment time, stirring time, etc.) and the target (composite conductivity), providing exceptional insight into the design and preparation ability of flexible carbon conductive materials. Specifically, we established an uni-component carbon filler database and proposed an optimized machine learning model based on Light Gradient Boosting Machine. The importance ranking of the characteristic variables in the fabrication of flexible carbon composites has been demonstrated in terms of the constructed uni-component carbon filler database. We trained our developed Light Gradient Boosting Machine model on selected data and attempted to predict the optimal design strategy for flexible carbon-based conductive materials in energy storage in smart wearable. The appealing results revealed effectiveness and dependability of Light Gradient Boosting Machine. The strategy established in this work presents an effective approach for accelerating the research and development of flexible carbon-based conductive materials in energy storage in smart wearable.     

Preparation and characterization of tungsten tailing-based geopolymers

Using tailings to prepare constructive materials is of great significance for sustainable development of mineral processing industry. In this study, the possibility of preparing tungsten tailing-based geopolymers was explored in detail. XRD, FTIR, PLM, SEM and XPS analyses were carried out to characterize the phase composition, chemical bonding, microstructure, chemical state, and interface properties of tungsten tailing-based geopolymers. Results showed tungsten tailings presented little activity using NaOH as activator, while geopolymers with 60% non-pretreatment tungsten tailing and 40% metakaolin presented a 3-day compressive strength of 8.4 MPa and 28-day compressive strength of 9.1 MPa. The geopolymerization products of tungsten tailing-based geopolymers were N-A-S-H gels and aluminosilicate zeolite crystals, while tungsten tailings were wrapped by metakaolin-derived geopolymerization phases as aggregates with interfaces containing Si–O–Si bonding between quartz in tungsten tailings and zeolite and/or gel phase in metakaolin-derived geopolymer in the geopolymerization process. Besides, the leaching test results indicated that the immobilization efficiency of T6M4 geopolymers for Mn and Pb derived from tungsten tailings reached up to 97.28% and 99.95%, respectively. This research results provide a new idea for utilization of tungsten tailings on a large scale.     

Highly Stretchable,Tough, and Conductive Ag@Cu Nanocomposite Hydrogels for Flexible Wearable Sensors and Bionic Electronic Skins

Flexible conductive materials and flexible electronic devices are driving the development of the next generation of cutting-edge wearable electronics. However, the existing hydrogel-based flexible conductive materials have limited tensile capacity, low toughness, and poor anti-fatigue performance, resulting in narrow sensing area and insufficient durability. In this paper, a conductive nanocomposite hydrogel with high ductility, toughness, and fatigue resistance is prepared by combining silver coated copper (Ag@Cu) nanoparticles with gelatin followed by one-step immersion in sodium sulfate (Na₂SO₄) solution. The salting-out of gelatin in Na₂SO₄ solution greatly improve the mechanical properties of this gelatin-based hydrogel. The uniform distribution of Ag@Cu nanoparticles inside the whole hydrogel endow the composite hydrogel with excellent electrical conductivity (1.35 S m⁻¹). In addition, it displayed high and stable tensile strain sensitivity over a wide strain range (gauge factor = 2.08). Therefore, the Ag@Cu-Gel hydrogel is sensitive and stable enough to be successfully utilized as flexible wearable sensor for detecting human motion signals in real time, such as bending of human joints, swallowing, and throat vocalization. Furthermore, this hydrogel is also suitable for application as electronic skin for bionic robots. The above results demonstrate the promising application of Ag@Cu-Gel hydrogel for wearable electronics.     

Sub-stoichiometric tungsten oxide by the stearic acid method

The synthesis of tungsten oxide by peroxotungstic route presents challenges, such as low solubility of tungstic acid in water and the fact that calcination product is a mixture of polytungstates. We propose a new route to obtain sub-stoichiometric tungsten oxides, using stearic acid, a non-toxic and low-cost material, as the dispersing and structuring agent for tungstic acid. The interaction between the precursor and the structuring agent was evaluated through chemical and structural analyses. Calcination of the stearic acid/tungstic acid systems produces vacant-rich monoclinic and orthorhombic tungsten oxides. Stearic acid plays a role of growth-directing agent and higher concentration of stearic acid promoted the growth of structures with plaque-shaped morphology in the samples, contributing to obtain sub-stoichiometric tungsten oxides, desired materials for visible light absorption.