不同制备温度下Ti2SnC增强银基复合材料的物相、微观组织和物理性能演变(英文)

大部分能源必须转化为电能才能为人类所利用，而在电能的传输和分配过程中，开关起着决定性作用。电触头是开关的核心组件，其质量和性能直接关系到终端设备工作的稳定性和安全性。长期以来，传统Ag/CdO复合电触头材料的毒性问题无法得到有效解决，而现有无Cd电触头材料(Ag/SnO₂、Ag/ZnO、Ag/C、Ag/Ni等)仍存在诸多问题。因此，开发新型环保高性能电触头增强相材料是低压开关用电触头发展的迫切需求和必然趋势。近年来，MAX相作为一种新型层状陶瓷材料，兼具金属的导电、导热、易加工和陶瓷的耐高温、耐腐蚀、稳定性好等双重特性，完全契合电触头增强相材料的性能要求，在银基复合电触头中展示出较强的开发和应用潜力。在已报道的MAX相家族中，Ti₂SnC的导电性最为优异，增强银基复合材料后对其在服役过程中保持低接触电阻和温升十分有利。因此，本工作选择Ti₂SnC作为Ag基增强相材料，研究制备工艺对复合材料结构和性能的影响。首先，本工作基于粉末冶金工艺在不同烧结温度下制备了Ag/10%Ti₂SnC(质量分数)(Ag/...     

高纯Ti_2AlC粉末的无压制备及其在Ag基电触头材料的应用（英文）

Ag基电触头是低压开关的"心脏",触头无Cd化一直困扰着人们,寻找新型环保电触头材料是目前低压开关领域研究的重点。本研究从Ag基电触头增强相材料设计入手,利用简单快速的无压技术合成了高纯Ti_2AlC粉末(99.2%),制备的Ag/Ti_2AlC复合电触头材料组织均匀、Ti_2AlC颗粒与Ag基体结合紧密、相对密度高(95.7%)、硬度适中(96HV)、导电性好(电阻率低至79.5nΩ·m)、抗电弧侵蚀性能优良(5610次电弧放电后触头质量损失仅为4.4wt%)。Ag/Ti_2AlC优良的结构和性能主要归因于Ti_2AlC本身的导电导热性能和Ag/Ti_2AlC之间的润湿性。该复合材料在进一步深入研究后,有望大面积应用并替代传统电触头材料。     

高纯Ti2AlC粉末的无压制备及其在Ag基电触头材料的应用

Ag基电触头是低压开关的“心脏”, 触头无Cd化一直困扰着人们, 寻找新型环保电触头材料是目前低压开关领域研究的重点。本研究从Ag基电触头增强相材料设计入手, 利用简单快速的无压技术合成了高纯Ti₂AlC粉末(99.2%), 制备的Ag/Ti₂AlC复合电触头材料组织均匀、Ti₂AlC颗粒与Ag基体结合紧密、相对密度高(95.7%)、硬度适中(96HV)、导电性好(电阻率低至79.5 nΩ·m)、抗电弧侵蚀性能优良(5610次电弧放电后触头质量损失仅为4.4wt%)。Ag/Ti₂AlC优良的结构和性能主要归因于Ti₂AlC本身的导电导热性能和Ag/Ti₂AlC之间的润湿性。该复合材料在进一步深入研究后, 有望大面积应用并替代传统电触头材料。     

新型组元触点材料及其电弧侵蚀研究进展

电触点材料广泛应用于电气开关、继电器、接触器以及断路器等各种低压开关器件中,其特性对整体电气系统的开关容量、可靠性、稳定性以及使用寿命具有极其重要意义。传统Ag基触点材料具有良好的抗熔焊及耐电弧烧蚀性能,但仍然存在接触电阻大、界面结合强度低、塑性差等缺陷,其应用也在一定程度上受到限制。近年来,国内外研究工作人员在传统Ag基触点材料的研究基础上报道了Ag-SnO₂-MeO、Ag-GNPs、Ag-MAX及Ag-RE等新型组元触点材料的研究工作。将从新型Ag基触点材料的发展背景出发,综述其组织与性能以及电弧侵蚀性能等方面的研究现状,最后总结新型Ag基触点材料面临的关键科学问题和挑战,并展望其未来的发展动向。     

Ti3AlC2陶瓷及其衍生物Ti3C2Tx增强的Ag基电接触材料

银基电触头在低压开关领域扮演重要角色。作为一种具有良好导电导热性能的新型二维碳化物材料,MXene家族典型代表材料(Ti₃C₂T_x)在多个领域显示出极大的应用潜力。Ti₃C₂T_x有望作为一种新型环保银基电触头增强相材料。本研究采用粉末冶金法制备了Ag/Ti₃C₂T_x复合材料,并对Ti₃C₂T_x和Ti₃AlC₂的物相和微观结构进行表征。同时研究了Ti₃C₂T_x增强Ag基复合材料的综合性能,包括电阻率、显微硬度、机械加工性能、抗拉强度和抗电弧侵蚀性能,并与Ti₃AlC₂增强Ag基复合材料进行了比较。Ag/Ti₃C₂T_x的电阻率(30×10 ^-3 μΩ·m)相对于Ag/Ti₃AlC₂(42×10 ^-3 μΩ·m)降低了29%。Ag/Ti₃C₂T_x硬度适中(64 HV),具有良好的可加工性,作为无毒电触头材料应用前景广阔。Ag/Ti₃C₂T_x复合材料导电性能的提高主要归因于Ti₃C₂T_x本身优异的金属性以及由Ti₃C₂T_x微观结构特征带来的可变形性。由于缺乏Al-Ag相互扩散,Ag/Ti₃C₂T_x复合材料的拉伸强度(32.77 MPa)明显低于Ag/Ti₃AlC₂复合材料(145.52 MPa)。正因为缺失Al层,Ag/Ti₃C₂T_x的抗电弧侵蚀性能也无法与Ag/Ti₃AlC₂相媲美。尽管Ag/Ti₃C₂T_x的抗电弧侵蚀性能有待进一步提高,但优异的导电性使其有望替代当下有毒的Ag/CdO电接触材料。该研究结果为开发新型环保电触头材料提供了新的探索方向。     

银基电接触材料的应用研究及制备工艺

鉴于银基电接触材料在电力系统、电器工业中的重要性,综合近年多种文献资料,阐述了Ag/Ni、Ag/C、Ag/WC和Ag/MeO等4个主要系列的银基电接触材料的特点.分析了喷射沉积法、溶胶-凝胶法、纤维强化法、等静压制法、等离子体喷涂法等制备银基电接触材料的工艺特点.结合现阶段研究工作,研制和改进电接触材料的制备工艺,发展新型环保触头材料、多相复合触头材料及纳米触头材料是今后银基电接触材料发展的主要方向.     

银金属氧化物触点材料电弧侵蚀退化机制研究进展

本文简述了银金属氧化物触点材料的发展历程,综述回顾了典型材料在服役过程中的电弧光谱特性、表面侵蚀结构演化、材料性能参数以及电弧侵蚀退化机制等方面的研究。结果表明：电弧持续时间、材料转移(或材料质量损失)、接触电阻等特征参数是导致电接触材料失效的关键因素,对电接触材料性能退化起到了决定性作用;优化灭弧室构造、非对称性配对、掺杂改性或引入磁性相等技术手段可以降低电弧持续时间,减轻表面烧蚀程度;借助电弧光谱学、数值计算与模拟仿真等技术,构建了触点材料的失效模式,包括“蒸发-分解-熔桥-喷溅”侵蚀模式、颗粒飞溅-沉积、常量k值模型等,在此基础上归纳了触点材料的设计原理与关键影响因素,为原创性研发全面替代Ag/CdO的高性能电接触材料奠定理论与应用研究基础。     

新型铜基电触头复合材料

<正>一、电触头材料的性能要求电触头是仪器仪表、电器开关中非常重要的接触元件。高压输变电大容量超高压发展,低压配电系统与控制系统对自动化水平、灵敏程度要求的提高以及电子工业产品的更新换代,都对触头材料提出了新的要求。电     

新型铜基电触头复合材制

一、电触头材料的性能要求 电触头是仪器仪表、电器开关中非常重要的接触元件。高压输变电大容量超高压发展,低压配电系统与控制系统对自动化水平、灵敏程度要求的提高以及电子工业产品的更新换代,都对触头材料提出了新的要求。电接触材料服役过程中经受电弧、电场、磁场、力、热及气氖等的共同作用,实现传导电流的使用性能。     

纳米Ag-SnO_2-TiO_2触头材料的制备工艺及性能研究

介绍了在纳米Ag SnO2 TiO2 触头材料制备过程中工艺参数的确定及触头性能。采用溶胶 凝胶法制备了SnO2 TiO2 混合纳米粉末 ,对压制成型的试样采用分级保温烧结的热处理方法 ,制得的触头材料的电导率为 6 6 .9%IACS ,密度为 9.6 3g cm3,硬度为 92 .3kg cm2 ,性能符合国标且优于美国和日本同类产品的 ,具有良好的应用前景     

Ag包复WC,C粉末触头材料的组织与性能

用化学镀在ＷＣ，Ｃ粉末表面包复了一层Ａｇ，改善了不同粉末间的浸润性，增强了颗粒间结合强度，使Ａｇ－ＷＣ－Ｃ系触头材料中各相分布均匀，性能提高。     

汽车继电器用AgMeO触点材料不同配对方式时的性能

为了探究触点配对方式对汽车继电器电接触性能的影响,选取AgMeO型触头材料进行实验,采用粉末冶金法制备AgSnO₂, AgCuO和AgZnO 3种触头材料,并测量其物理性能,采用JF04C电接触触点材料测试系统,按5种不同触点配对方式进行电接触实验,并对实验前后的阴阳极触点进行称量,实验结果表明：触点配对方式对接触电阻,材料转移和损耗影响较大,对燃弧能量的影响较小,通过对触点进行不对称配对可以明显降低接触电阻和材料转移和损耗,明显改善汽车继电器的接触性能.     

Interface Structure of Ag/SnO2 Nanocomposite Fabricated by Reactive Synthesis

The electric contact material of Ag/SnO₂ composite was achieved by reactive synthesis method. The com-positions and microstructure of Ag/SnO₂ composite were analyzed and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and high-resolution electron microscopy (HRTEM). The structural feature was typical of the particle reinforced composites. The HRTEM images revealed that the observed Ag/SnO₂ interface was absence of the precipitated phase and the lattice contrast across the interface was clear and sharp. The average particle size of SnO₂ in composite was near 50 nm and it was well dispersed in spherical shape. The thermodynamic mechanism of reactive synthesis method was also discussed. The electronic density distribution analysis of the interface showed the charges of Ag atoms transmitted to O atoms and the conductivity of the material was also affected. No extra compounds expected such as Ag_xO_y formed at interface. The distribution of electrons was of inequality near the interface which explained why the mechanical property of the metal/ceramic materials was improved but the machining property declined.     

Influence of Metal Oxides on the Arc Erosion Behaviour of Silver Metal Oxides Electrical Contact Materials

In the present work investigations have been made to see the role of metal oxides on the performance of the silver metal oxides electrical contact materials. Silver metal oxide materials of three different compositions Ag-10CdO, Ag-7.6SnO2-2.3ln2O3 and Ag-10ZnO were prepared by internal oxidation process under identical processing conditions. These materials were tested for electrical conductivity, hardness, and erosion loss. Performing an accelerated test on the actual contactor assessed the electrical performance, involving erosion loss and temperature rise of the processed materials. The arc-eroded surface was characterized under scanning electron microscope. The study of the eroded surfaces of contacts indicates that the thermal stability of metal oxides depends on nature of silver-metal oxide interface and their mode of erosion. An attempt is made to correlate the surface features of the eroded contacts with the thermal stability of metal oxides.     

Lowering the Schottky Barrier Height by Graphene/Ag Electrodes for High‐Mobility MoS2 Field‐Effect Transistors

2D transition metal dichalcogenides (TMDCs) have emerged as promising candidates for post‐silicon nanoelectronics owing to their unique and outstanding semiconducting properties. However, contact engineering for these materials to create high‐performance devices while adapting for large‐area fabrication is still in its nascent stages. In this study, graphene/Ag contacts are introduced into MoS₂ devices, for which a graphene film synthesized by chemical vapor deposition (CVD) is inserted between a CVD‐grown MoS₂ film and a Ag electrode as an interfacial layer. The MoS₂ field‐effect transistors with graphene/Ag contacts show improved electrical and photoelectrical properties, achieving a field‐effect mobility of 35 cm² V^?1 s^?1, an on/off current ratio of 4 × 10⁸, and a photoresponsivity of 2160 A W^?1, compared to those of devices with conventional Ti/Au contacts. These improvements are attributed to the low work function of Ag and the tunability of graphene Fermi level; the n‐doping of Ag in graphene decreases its Fermi level, thereby reducing the Schottky barrier height and contact resistance between the MoS₂ and electrodes. This demonstration of contact interface engineering with CVD‐grown MoS₂ and graphene is a key step toward the practical application of atomically thin TMDC‐based devices with low‐resistance contacts for high‐performance large‐area electronics and optoelectronics.     

Arc erosion behavior of Ag/Ni electrical contact materials

Ag/Ni electrical contact materials tend to be weld together under high current and/or high temperature, which was a key problem to restrict the usage of Ag/Ni electric contact materials. Arc erosion characteristics of Ag/12Ni electrical contact material after 50,000 operations under direct current 19 V, 20 A and resistive load conditions were investigated. The result indicated that the probability distribution and change trend of arc energy and arc time during 50,000 operations were similar and the relationship between arc time and arc energy followed exponential function. On the one hand, “Crater” type erosion pit, island-like melted silver, pore, crack and coral-like structure spitting were observed on erosion surface of Ag/Ni contact materials. On the other hand, distribution of Ag and Ni element on molten pool of movable contact was different from that of stationary contact. For movable contact, element Ni mainly distributed on melted pool root, whereas element Ag mainly distributed inside of melted pool. For stationary contact, however, element Ni and Ag distributed layer by layer. Furthermore, arc erosion of stationary contact is more serious than that of movable contact.     

Optimum structure of metal oxide under-layer used in Ag-based multilayer

The effects of a metal oxide under-layer on the resistivity of a Ag layer were investigated. Ag-based multilayers, which have a layer construction of glass/ZnO under-layer/Ag/ZAO (Al-doped ZnO) blocker/ZnO top layer, were deposited by DC magnetron sputtering with changing the sputter gas pressure during the under-layer deposition and it was confirmed that the Ag layer showed low resistivity when the smooth crystallized ZnO under-layer was employed. On the other hand, in the case of the Ag-based multilayer using the smooth amorphous-SnO₂ under-layer, it was found that the Ag layer was poorly crystallized and showed higher resistivity than the Ag layer using the ZnO under-layer. This comparative study indicated that the ZnO under-layer promoted the preferred crystal growth of the Ag layer.