不同陶瓷颗粒增强Cu基复合材料的制备及导电性能

以纯铜为基体,以WC、AlN、TiN、MgB2等具有不同导电性能与密度的陶瓷颗粒为增强相,采用球磨-冷压-烧结工艺制备了WCp/Cu、AlNp/Cu、TiNp/Cu和MgB2p/Cu系列复合材料.研究了制备工艺的不同环节对铜基复合材料导电性能的影响,讨论了不同陶瓷颗粒增强铜基复合材料的导电性能.结果表明相同制备工艺及体积分数条件下,以具有不同导电性能与密度的陶瓷颗粒作为增强相的铜基复合材料的导电性能相近,球磨、冷压、烧结、复压及复烧等工艺环节对铜基复合材料导电性能有不同程度的影响,提高铜基复合材料的致密度为提高其导电性能的关键.     

原位化学法制备纳米ZrO2/Cu复合材料的研究

为了提高铜基复合材料的强度和电导率,采用具有良好机械性能和热物理性能的ZrO2(3%(摩尔分数)Y2O3)作为增强相,原位化学法制备了ZrO2纳米颗粒增强铜基复合材料,其主要制备工艺包括前驱复合粉体CuO、ZrO2的制备,经氢气还原得到ZrO2/Cu复合粉,再经过压制,真空烧结,复压等工序制得最后的样品.研究了制备工艺包括初压压力,烧结温度、时间对材料性能的影响;结果表明,在初压压力为550MPa,975℃烧结1.5h时,可得到最佳性能复合材料.透射电镜观察表明,在ZrO2/Cu纳米复合粉中,氧化锆纳米颗粒形状为圆形和四方形,平均尺寸约为20nm左右.纳米ZrO2在基体中分布均匀,细化了晶粒,提高材料硬度,使复合材料具有良好的综合性能.随着ZrO2含量的提高,密度、电导率降低,硬度升高.     

颗粒增强铜基复合材料的研究进展

为了研究颗粒增强相对铜基复合材料的性能的影响,对不同类型铜基复合材料的特点及其制备方法进行对比分析,探讨了颗粒相的生成机制,重点论述了颗粒增强相的类型及铜基复合材料的制备工艺.结果表明在铜基体中引入纳米分散相进行复合,可以使铜合金的力学性能得到极大改善,其中机械合金化和原位复合化学反应获得的纳米陶瓷颗粒在铜基复合材料中效果最佳;反应喷射沉积成型法、液相反应原位生成法和机械合金化法在制备纳米粒子增强铜基复合材料方面有着良好的应用前景.     

石墨烯增强铜基复合材料的界面调控及其性能研究进展

铜基复合材料有望全面提升铜及铜合金的力学性能和导电、导热等功能特性。石墨烯具有优异的力学和物理性能,是铜基复合材料的理想增强相。石墨烯/铜界面的性质决定了复合材料性能,进行界面调控以提高石墨烯/铜的界面结合性已成为研究人员关注的热点问题。总结了近几年开发的石墨烯缺陷设计法、碳-碳杂化增强相法、金属和陶瓷纳米颗粒修饰石墨烯法以及原位生长石墨烯和石墨烯复合增强相法等多种界面调控策略,讨论了多种界面调控策略对石墨烯增强铜基复合材料的力学、导电、导热性能的作用机理,展望了应用界面调控策略研发的高性能复合材料的应用前景和未来研发的发展方向。     

纳米Cu-Al2O3复合材料的烧结法制备研究

研究了纳米Al2O3陶瓷颗粒增强铜基复合材料制备技术.选用纳米级Al2O3陶瓷颗粒作为增强相,采用超声波增强化学镀的方法完成对纳米Al2O3陶瓷颗粒金属铜包覆,热压烧结成纳米Al2O3陶瓷颗粒增强铜基复合材料,开采用XRD、TEM等分析测试技术对其组织性能进行研究.     

颗粒增强铜基复合材料研究进展

颗粒增强铜基复合材料在基本保持金属铜优良导电和导热性能的基础上大大提高了铜基复合材料的强度和耐磨性,是一种具有良好发展前景的复合材料.回顾了近年来颗粒增强铜基复合材料的增强相和制备方法的发展,并指出了今后研究发展的方向.     

石墨烯增强铜基复合材料研究进展

铜(Cu)基复合材料具有优异的力学、热学、电学及耐磨和耐腐蚀等性能,广泛应用于各种工业技术领域。石墨烯(Graphene,Gr)具有二维平面结构和优异的综合性能,是金属基复合材料理想的增强相。石墨烯增强铜基复合材料拓展了铜及其合金的应用范围,适当的制备方法可以使其在保持优异导电导热性能的同时拥有更好的力学性能。石墨烯在铜基体中的存在形式主要以还原氧化石墨烯、石墨烯纳米片或与金属氧化物/碳化物纳米颗粒连接,旨在增强两者之间的界面结合。因此,石墨烯在铜基体中的结构完整性及存在形式直接影响了其性能的优劣。本文综述了Cu/Gr复合材料的制备及模拟方法、复合材料的性能评价及力学性能与功能特性的相互影响规律。指明Cu/Gr复合材料的发展关键在于：(1)分散性与界面结合;(2)三维石墨烯结构的构建;(3)界面结合对力学性能与功能特性的影响及两者间的相互协调。     

铜基复合材料的研究

综述了7种制备铜基复合材料的工艺机理、特点,以及Cu/Al2O3,Cu/WC,Cu/TiB2,Cu/Ti3SiC2 4种复合材料的研究进展.内氧化法主要用于制备Cu/Al2O3复合材料,其氧含量控制困难,成本昂贵;机械合金化法可制备超细颗粒强化的铜基复合材料,具有工艺简单,成本相对较低的特点,缺点是耗能大,易混入杂质;溶胶-凝胶法可制备超细氧化铝强化的铜基复合材料,工艺过程易控制;液相反应法可用来制备性能优良的Cu/5%TiB2复合材料,基体中颗料的含量、尺寸和分布易控制;固相反应生成法产品纯度高,易获得复杂相和亚稳定相,但产品致密度不高;反应喷射沉积法制得的产品晶粒细小,无宏观偏析,颗粒分布均匀,生产工艺简单,生产效率高.最后还分析了铜基复合材料研究中存在的问题.     

铜基无颗粒型导电墨水的性能研究

目的通过测定导电涂层电阻率来确定导电墨水的最佳制备工艺参数。方法以醋酸铜为前驱体,N,N-二甲基乙醇胺为络合剂,甲酸为还原剂,制备导电性高的铜基无颗粒型导电墨水。采用化学还原法制备铜基无颗粒型导电墨水,通过正交实验研究烧结温度、烧结时间以及Cu2+∶H+∶NH4+的比例对涂层导电性的影响,确定最佳的制备工艺。结果制备的铜基无颗粒型导电墨水在弱碱性环境下较稳定,墨水中的Cu2+,H+,NH4+的最佳物质的量之比为1∶3∶3。该配方的墨水具有很高的稳定性能和导电性能,在玻璃基材上滴涂经160℃下热处理30 min,得到的涂层电阻率仅为0.18μ?·m。结论初步实现了铜基无颗粒型导电墨水的低温烧结。     

高能球磨法制备铜基电触头复合材料的研究

研究了高能球磨法在制备铜基电触头复合材料的工艺中对电触头的组织结构、力学性能和导电性能的影响,并对复合材料粉末中B4C颗粒的形貌、粒度以及在铜基体中的分布情况进行了研究.试验结果表明,高能球磨法对改变增强颗粒的形貌、改善增强颗粒体的分布均匀性非常有效,而且可以有效地提高触头材料的硬度和耐磨性.     

Effect of size and shape of metal particles to improve hardness and electrical properties of carbon nanotube reinforced copper and copper alloy composites

Utilizing the extra-ordinary properties of carbon nanotube (CNT) in metal matrix composite (MMC) for macroscopic applications is still a big challenge for science and technology. Very few successful attempts have been made for commercial applications due to the difficulties incorporating CNTs in metals with up-scalable processes. CNT reinforced copper and copper alloy (bronze) composites have been fabricated by well-established hot-press sintering method of powder metallurgy. The parameters of CNT–metal powder mixing and hot-press sintering have been optimized and the matrix materials of the mixed powders and composites have been evaluated. However, the effect of shape and size of metal particles as well as selection of carbon nanotubes has significant influence on the mechanical and electrical properties of the composites. The hardness of copper matrix composite has improved up to 47% compared to that of pure copper, while the electrical conductivity of bronze composite has improved up to 20% compared to that of the pure alloy. Thus carbon nanotube can improve the mechanical properties of highly-conductive low-strength copper metals, whereas in low-conductivity high-strength copper alloys the electrical conductivity can be improved.     

Microstructure,mechanical properties,electrical conductivity and wear behavior of high volume TiC reinforced Cu-matrix composites

This study deals with the processing, microstructure, mechanical properties, electrical conductivity and wear behavior of high volume titanium carbide reinforced copper matrix composites. The microstructural study revealed that the titanium carbide particles were distributed uniformly in the matrix phase. No interface debonding and micro-cracks were observed in the composite. The addition of alloying elements in the copper considerably increased the sintered density and properties. The composite hardness and strength increased with titanium carbide content and alloying elements in the matrix phase. The electrical conductivities of the composites were predicted using three point upper bound and two phase self consistent predictive models. The wear resistance of the composites was studied against high speed steel. Wear mechanisms were discussed by means of microscope observations on the worn surfaces. The ratio of titanium carbide average grain size to the mean free path of the binder was introduced as a parameter to determine wear performance.     

石墨烯添加量对铜基复合材料性能的影响

采用一步化学还原法结合放电等离子烧结工艺制备石墨烯增强铜基复合材料,利用XRD、SEM、拉曼光谱、拉伸试验机、纳米压痕仪、涡流电导率仪等研究石墨烯含量对复合材料微观组织、力学性能和导电性能的影响。结果表明:石墨烯在复合材料基体中均匀分布,石墨烯的添加能显著增强铜基体的力学性能。与纯铜相比,添加0.025%(质量分数)的氧化石墨烯,可使其屈服强度提高219.8%,抗拉强度提高35.9%,弹性模量提高6.9%,此外,其导电率仍有93.1%IACS。随着石墨烯含量的增加,复合材料的屈服强度、抗拉强度及弹性模量均有所下降,这是因为高石墨烯含量复合粉体中部分石墨烯纳米片未能被铜颗粒包覆,其与铜基体界面结合强度低,石墨烯的剪切应力转移强化效果降低。     

Microstructure and electrical conductivity of Al-SiCp composites produced by spray forming process

Al- SiC_p composites have been synthesized by spray forming process with variation in particle flow rate, size of reinforcement particles and their volume fraction. The microstructure of composites and their electrical conductivity have been investigated. The results showed a uniform dispersion of large size particulate phase in the matrix of the primary α- phase with its equiaxed grain morphology. However, clustering of small size particles was observed at the grain boundary and grain junctions. The grain size of the composite materials was observed to be lower than that of the base Al- alloy. The composite materials invariably indicated their lower electrical conductivity compared to that of the monolithic Al- alloy. The electrical conductivity of composites decreased with increase in the volume fraction and decrease in size of the reinforcement particles. A high flow rate of particles during spray deposition resulted in a decrease in its conductivity. These results are explained in the light of thermal mismatch between the matrix and the reinforcement phases resulting in generation of high dislocation density. The droplet- particle interaction and resulting microstructure evolution during the spray deposition of the composites are discussed.     

Microstructure,Properties and Wear Behaviors of (Ni_3Al)_p Reinforced Cu Matrix Composites

Pure copper and its composites reinforced with Ni 3 Al particles were produced by powder metallurgy(PM).Ni 3 Al powders were produced by mechanical ball milling from vacuum arc melted compounds.The Ni 3 Al powders were characterized by X-ray diffraction(XRD).The microscopy examinations revealed that the Ni 3 Al particles were distributed uniformly in the matrix.The effects of the particle fraction on the density,electrical conductivity,strength and dry sliding wear resistance of composite were investigated.It was found that the density and electrical conductivity of the composites decrease while the compression yield strength and wear resistance of composites increase with an increase in the particle fraction.The dry sliding wear tests were performed with pin-on-disk geometry.After sliding wear tests,the worn surfaces were examined by scanning electron microscopy(SEM) equipped with an energy dispersive X-ray spectrometer(EDS).Results have shown that the wear mechanism is oxidative and adhesive.     

一种新的β-锂霞石增强铜基复合材料热性能

采用热压烧结工艺成功制备了一种新的β-锂霞石增强铜基复合材料.利用扫描电镜和透射电镜对复合材料的微观组织进行了分析,并对不同体积分数复合材料的致密性,热膨胀性能和热传导性能进行了测试.结果表明:β-锂霞石颗粒在铜基体中分布均匀,界面清晰,不发生界面反应;体积分数对复合材料致密性、热膨胀系数和热导率有明显影响,当β-锂霞石颗粒体积分数超过40%时,复合材料的致密性有明显下降,热膨胀系数在(9～15.4)×10-6/K,同时热导率在50～170W/m·K.     

铜基石墨复合材料的研究进展

铜基石墨复合材料是一种广泛应用于摩擦材料和电接触材料等领域的金属基复合材料.综述了铜基石墨复合材料在改善铜基体与石墨增强体结合方面的研究进展,主要包括基体合金化、石墨的表面处理、添加粘结剂等,重点介绍了铜基石墨复合材料的制备工艺方法,并概述了其导电导热性能、摩擦磨损性能、工艺性能及应用,最后展望了铜基石墨复合材料的研究重点和发展方向,认为取代现有的易切削铅黄铜合金将成为铜基石墨复合材料今后研究和应用的一个亮点.     

Effects of copper and Al2O3 particles on characteristics of Cu–Al2O3 composites

High-energy milling was used for production of Cu–Al₂O₃ composites. The inert gas-atomized prealloyed copper powder containing 2 wt.%Al and the mixture of the different sized electrolytic copper powders with 4 wt.% commercial Al₂O₃ powders served as starting materials. Milling of prealloyed copper powders promotes formation of nano-sized Al₂O₃ particles by internal oxidation with oxygen from air. Hot-pressed compacts of composites obtained from 5 and 20 h milled powders were additionally subjected to the high-temperature exposure in argon at 800 °C for 1 and 5 h. Characterization of processed material was performed by optical and scanning electron microscopy (SEM), X-ray diffraction analysis (XRD), microhardness, as well as density and electrical conductivity measurements. Due to nano-sized Al₂O₃ particles microhardness and thermal stability of composite processed from milled prealloyed powders are higher than corresponding properties of composites processed from the milled powder mixtures. The results were discussed in terms of the effects of different size of starting copper powders and Al₂O₃ particles on the structure, strengthening of copper matrix, thermal stability and electrical conductivity of Cu–Al₂O₃ composites.     

电铸制备铜-石墨复合材料的研究

在酸性硫酸铜溶液中采用电铸技术制备了铜-石墨复合材料.表面活性剂、微粒浓度、电流密度和搅拌速度等工艺条件对微粒含量具有不同的影响.非离子表面活性剂对微粒共沉积具有较好的效果;随着微粒浓度增大,微粒含量也逐渐增大,最后趋于稳定值;电流密度增大使微粒含量降低;搅拌速度增大时微粒含量存在最大值.铜-石墨复合材料的硬度和摩擦系数随着微粒含量增大而减小,但是磨损量先是减小而后增大.摩擦过程中纯铜发生粘着磨损,铜-石墨复合材料却表现为剥层磨损.     

Influence of carbon nanotubes and dispersions of SiC on the physical and mechanical properties of pure copper and copper‐nickel alloy

This paper investigates the physical and mechanical properties of copper‐nickel alloy (at 50 wt.%–50 wt.%) and pure copper, mixed with various types of reinforcement materials such as carbon nanotubes (0.5 wt.%–2 wt.%) as nanoparticles, silicon carbide (1 wt.%–4 wt.%) as microparticles. The acquired composite specimens characteristics were estimated such as microstructure, density, electrical and thermal conductivity, hardness, and compression stress properties to determine the suitable reinforcement percentage that has the best physical and mechanical properties with different main matrix material whether copper‐nickel mechanical alloying or pure copper powder. The micron‐sized silicon carbide and nanosized carbon nanotubes were added to improve the mechanical and physical properties of the composite. The electrical and thermal conductivity of pure copper alloy enhanced compared with the copper‐nickel alloy matrix material. The hardness and compression yield stress of both pure copper and copper‐nickel composites have enhancement values and for copper‐nickel base composites hardness and compression yield stress have enhanced with the most positive enhancement values to examined an optimum percentage of reinforcing material.