石墨烯增强铜基复合材料的制备技术及发展

石墨烯由于其独特的二维结构和优异的物化性能,在改善复合材料的力学性能、电学性能和热学性能等方面具有很大的潜力,已成为金属基复合材料较理想的增强体。铜合金具有优异的导电导热性能和良好的延展性,但是其强度较低、不耐磨及高温下易变形的特点阻碍了其应用和发展。因此,结合石墨烯和铜的性能特点,将石墨烯作为增强体添加到铜中,制备性能优异的石墨烯增强铜基复合材料成为目前研究的热点之一。综述了目前石墨烯增强铜基复合材料的制备方法,并对各方法的特点进行了分析比较,提出未来可采用的制备工艺的方向以及在制备过程中面临的问题和挑战,并对其未来的研究方向进行了展望。     

含石墨烯胞室结构的铜复合材料及其耐腐蚀性能

目的 开发一种石墨烯在铜基复合材料中的均匀分散结构,制备出兼具高导电和强抗刻蚀性能的石墨烯/铜复合材料。方法 采用化学气相沉积原位生长法结合分散剂工艺,制备分散均匀石墨烯/铜基粉体复合材料。利用制备的石墨烯/铜粉体材料,采用真空热压工艺,制备了石墨烯/铜块体材料,然后用拉曼光谱、X射线粉末衍射仪和金相显微镜,考察石墨烯/铜试样的质量和形貌,最后用数字便携式涡流电导仪测量其电导率。利用自主设计的石墨烯/铜在过硫酸铵中刻蚀的实验装置,测试石墨烯/铜的抗刻蚀性能。结果 利用石墨烯/铜粉体制备的石墨烯/铜块体和铜具有相同的(111)、(200)和(220)晶面,多层石墨烯以立体胞室结构均匀分布在铜晶粒的晶界处。石墨烯/铜块体的导电率为96%IACS,明显优于文献报道的以其他方法制备的石墨烯/铜块体,并且在过硫酸铵溶液中浸泡90 min后,石墨烯/铜块的质量损失为126.6 mg, 石墨烯/铜比纯铜的抗刻蚀能力提高了37.6%,具有比铜更强的抗刻蚀性能。结论 以CVD原位生长法和真空热压法制 备的石墨烯/铜复合材料,石墨烯以立体胞室结构均匀分散在铜界面处,并且兼具高的导电性和强的抗刻蚀性能。     

High-Speed Tribological and Mechanical Properties of Layered Fe/SiC Composites

In this work, we studied the high-speed tribological and mechanical properties of layered SiC particulate reinforced iron matrix composites. The layered composites consisted of a surface layer with high volume fraction of the reinforcement particles and a layer with low volume fraction in the bulk. The layered composites are a form of functionally graded materials with high wear resistance near the surface and high thermal conductivity in the bulk. The composites were prepared by standard powder metallurgy techniques. The tribological behavior of the composites was evaluated at 25 to 35 m/s sliding speeds using a sub-scale dynamometer disk brake testing system. The properties of the layered composites were compared to those of uniform composites. The results showed that the layered composites have better wear resistance and braking effectiveness in the range of braking speeds considered. The layered composites also showed higher bending strength than the monolayer composites due to the presence of the interfaces between the layers.     

Preparation and properties of Cu matrix composite reinforced by carbon nanotubes

Cu matrix composites reinforced by carbon nanotubes(CNTs) were prepared. The effect of carbon nanotubes on mechanical and tribological properties of the Cu matrix composites were investigated. The chemical method for coating CNTs was reported. The morphology of the fracture surfaces and worn surface were examined by SEM.The results show that Cu/coated-CNTs composites have higher hardness, much better wear resistance and antifriction properties than those of the reference Cu alloy (Cu-10Sn) and Cu/uncoated-CNTs composite sintered under the same conditions. The optimal mechanical properties of the composites occurred at 2. 25%(mass fraction) of CNTs. The excellent wear resistance and anti-friction properties are attributed to the fiber strengthening effect of CNTs and the effect of the spherical wear debris containing carbon nanotubes on the tribo-surface.     

放电等离子烧结法制备石墨烯-铜铬锆合金的组织与性能

采用低能球磨和放电等离子烧结法制备了石墨烯(GNPs)增强铜基复合材料.研究了石墨烯含量对复合材料微观结构和性能的影响.结果 表明,随着石墨烯含量的增加,复合材料的力学性能呈现出先升高后降低的趋势.其中,当石墨烯含量为0.25％(质量分数)时,复合材料的极限抗压强度为409 MPa,合金的导电率高达90％ IACS.石...     

变形方式对Cu-8.3Fe-1Ag形变原位复合材料组织性能的影响

分别采用冷拉拔和冷轧变形并结合中间退火工艺,制备了丝状和带状形变Cu-8.3Fe-1Ag原位复合材料。用SEM、精密万能试验机、显微硬度计和电阻测量仪对两种变形方式下试样的微观组织、力学性能和导电性能进行了比较研究。微观组织观察表明:冷拉拔和冷轧变形试样的横截面组织形貌有显著差异,前者为基体上分布着弯曲、扭折、交叠的蠕虫状相,后者为基体上定向排列着与冷轧方向平行的平直颗粒相。力学性能和导电率测试结果表明:相同应变量下,冷拉拔变形的抗拉强度、硬度均高于冷轧变形,但二者的导电率几乎相同。应变量达到6.70时,二者的抗拉强度/硬度/导电率分别达到838 MPa/149 HV/58%IACS和924 MPa/160 HV/58%IACS。     

BN与LPSO相混杂增强的镁基复合材料制备及性能

研究了六方氮化硼(h-BN)颗粒增强镁基复合材料的制备工艺及其性能。通过化学镀法在h-BN颗粒表面包覆一层纯镍,镀镍处理能显著改善h-BN与镁合金熔体的润湿性,改善其与基体的界面结合。通过向基体合金中加入Y元素,利用镀镍层熔入熔体中的Ni获得了由Mg-Ni-Y组成的LPSO结构(长周期堆垛有序结构),制得了h-BN+LPSO混杂增强的镁基复合材料。超声处理后,hBN增强相体积分数为3%的镁基复合材料热导率为99.92W/(m·K),室温(RT)至100℃的平均热膨胀系数为18.36×10^-6K^-1,抗拉强度为171MPa,伸长率为3.9%,获得了兼具较高力学性能和优异热物性能的镁合金材料。     

石墨烯对搅拌摩擦加工铝基复合材料性能的影响

采用结合粉末工艺的两步法搅拌摩擦加工制备石墨烯增强铝基复合材料,研究了石墨烯添加量对复合材料力学性能和导电性能的影响。结果表明,石墨烯的添加对铝基复合材料性能有明显的影响,随石墨烯添加量增加,复合材料的硬度逐渐提高、塑性持续下降,而抗拉强度和电导率均呈先增后减的趋势。石墨烯体积分数为3.7%时,复合材料的抗拉强度最高,达到146.5 MPa,与同等加工条件下的纯铝相比,提高了78.7%,而石墨烯体积分数为1.3%时,复合材料的电导率最高,达到30.62 MS/m,较同等加工条件下的纯铝基体提高了53.4%。     

铜基复合材料中短碳纤维增强体表面镀铜的研究现状

短碳纤维增强铜基复合材料是一种极具发展前景的金属基复合材料。但是碳纤维和铜的浸润性很差,一般须对短碳纤维进行表面镀铜处理。主要介绍了短碳纤维表面电镀铜和化学镀铜工艺,从工艺流程等方面分析其优缺点,并探讨了短碳纤维化学镀铜未来的研究方向。以甲醛为还原剂得到的镀层铜纯度接近100%,以此制成的铜基复合材料的导电性也较优异,但甲醛对人体有害和污染环境。次磷酸钠还原体系的化学镀铜工艺无毒无害,但需对碳纤维进行敏化活化处理。如何简化次磷酸钠还原体系化学镀铜工艺,提高镀铜层的纯度将是今后研究发展的重点。     

Characterization and Tribological Properties of Graphene/Copper Composites Fabricated by Electroless Plating and Powder Metallurgy

Self-lubricating copper matrix composites reinforced with graphene were prepared by electroless plating and powder metallurgy.The morphology and structure of graphene,Cu@graphene powder,and Cu@graphene/Cu composites were characterized and the tribological properties of Cu@graphene/Cu composites were investigated.The X-ray diffraction pattern of Cu@graphene confirms the coexistence of characteristic peaks of both copper and graphene,with a weakened characteristic peak of carbon impurity.The obtained morphology of Cu@graphene reveals that the surface of the graphene is completely covered with a uniform and compact copper layer with lots of copper nanoparticles.Raman and Fourier transform infrared spectroscopy analyses show that the oxygen functional groups and defects on the surface of the redox graphene can be reduced through the electroless plating process.The tribological results indicate that the coefficient of friction of Cu@graphene/Cu composites initially decreases and then increases with an increase in Cu@graphene content.The lowest coefficient of friction,which is about 29.47% lower than that of pure Cu,is achieved in the Cu@graphene/Cu composites with 3.0 wt%Cu@graphene.The chemical composition and topography of the wear tracks for Cu@graphene/Cu composites infer that the formation of a well-consolidated graphene-rich lubricious tribolayer at the contact surface and a higher microhardness work together to enhance the tribological performance of Cu@graphene/Cu composites.     

Electrical conductive epoxy composites containing cilia-like powders fabricated by mechanical milling

Electrically conductive epoxy composites were developed by adding cilia-like powders produced by dispersing multi-walled carbon nanotubes (MWNTs) on copper particles via mechanical milling. During the milling process, the MWNTs were gradually dispersed and partially embedded in the copper particles, producing cilialike powders that enhanced the electrical conductivity of the epoxy composites. With further milling, however, excessive embedding of the MWNTs in the copper particles resulted in decreased electrical conductivity. Electrical conductivity of the epoxy composites containing 24 vol.% of the cilia-like powders (milled for 1 h) was remarkably enhanced up to 15 S/cm.     

Ti3SiC2陶瓷颗粒表面超声波化学镀铜

钛碳化硅（Ti3SiC2）陶瓷导电材料有许多优异的性能,其摩擦系数甚至比石墨更低,完全可以取代石墨用来制备性能更加优良的铜基电接触复合材料,但是由于其与铜基体之间的浸润性不是很好,研究了利用超声波化学镀覆技术在Ti3SiC2颗粒表面均匀镀上一层连续的铜镀层。通过扫描电子显微镜对铜镀层表面形貌的观察表明：通过严格的镀前预处理工艺的优化设计以增加活化点,对传统镀液配方的调整以降低镀速,能够成功的在Ti3SiC2颗粒表面均匀镀覆一层铜微粒,改善了Ti3SiC2和铜基体间的润湿性,从而增强二者之间的界面结合力。     

Ti3SiC2陶瓷颗粒增强铜基复合材料的组织和性能

为了考察Al,Sn,Zr,Mo合金元素对α钛合金在室温和77 K低温（液氮）下的缺口冲击韧性（冲击值Ak）的影响,采用示波冲击试验机测试了Ti-2Al,Ti-2Sn,Ti-2Zr和Ti-1Mo 4种α钛合金在室温和77K下的Ak值,并计算了表征其冲击韧性的弹性变形功、塑性变形功和裂纹扩展撕裂功.用扫描电镜观察了4种合金冲击试样断口的形貌.计算数据和显微组织表明,4种合金均显示韧性特征,4种合金元素对冲击韧性贡献的顺序为：Mo＞Zr＞Sn＞Al.     

Physical,Mechanical, and Tribological Attributes of Stir-Cast AZ91/SiCp Composite

In the present investigation, composites with silicon carbide particle （SiCp） as reinforcement and AZ91 magnesium alloy as matrix have been synthesized using liquid metal stir-casting technique with optimized processing conditions. The composites with good particle distribution in the matrix, and better grain refinement and good interfacial bonding between the matrix and reinforcement have been obtained. The effect of SiCp content on the physical, mechanical, and tribological properties of Mg-based metal matrix composite （MMC） is studied with respect to particle distribution, grain refinement, and particle/matrix interfacial reactions. The electrical conductivity, coefficient of thermal expansion, microas well as macro-hardness, tensile and compressive properties, and the fracture behavior of the composites along with dry sliding wear of the composites have been evaluated and compared with the base alloy.     

混杂增强(CNTs+TiB2)/Cu复合材料制备与性能

本文以碳纳米管（CNTs）和TiB2颗粒作为增强相,首先利用球磨、表面吸附和热压烧结相结合技术制备具有层叠结构的CNTs/Cu复合材料,改善了CNTs在铜基复合材料中易团聚问题。CNTs/Cu复合材料的致密度和导电率随CNTs含量增加而降低,抗拉强度和伸长率随CNTs含量增加先升高后降低,当含量为0.1 wt.%时综合性能最优,致密度、导电率和抗拉强度分别为97.57%、91.2 %IACS和252 MPa。而球磨后热压烧结的1 wt.% TiB2/Cu复合材料致密度、导电率和抗拉强度分别为97.61%、58.3 %IACS和436 MPa。在此基础上,将TiB2颗粒原位引入到具有层叠结构的CNTs/Cu复合材料,制备获得混杂增强(CNTs+TiB2)/Cu复合材料。相比单一CNTs（或TiB2）增强铜基复合材料,(CNTs+TiB2)/Cu复合材料的强度提升显著。其中,(0.1 wt.% CNTs+1 wt.% TiB2)/Cu复合材料的导电率和抗拉强度分别为56.4 %IACS和531 MPa,相比1 wt.% TiB2/Cu,其导电率仅降低3.3%,而抗拉强度则升高21.8%。这主要归因于片层间CNTs可起承担和传递载荷作用,同时片层间弥散分布的TiB2颗粒可以钉扎位错,两种强化机制共同作用使(CNTs+TiB2)/Cu复合材料的抗拉强度显著提升。     

碳纳米管增强铜基复合材料的制备、力学性能及电导率

以CNTs、电解Cu粉、Cu(CH_3COO)_2·H_2O为原料,采用混酸处理、分子水平法结合行星球磨两步混合工艺制备含0.5%～2%(质量分数)CNTs的Cu基复合粉末,然后通过放电等离子烧结技术制备了Cu-CNTs复合材料,探讨了制备工艺及CNTs含量对Cu-CNTs复合材料的组织、电导率和力学性能的影响规律。结果表明:当CNTs含量小于1.0%时,采用两步混粉工艺制备的Cu-CNTs复合粉体均匀性、分散性良好,经烧结后可获得致密度高、CNTs分布均匀的Cu-CNTs复合材料;当CNTs含量大于1.0%时,复合材料的致密度及CNTs分布均匀性明显降低;随CNTs含量的提高,复合材料的强度先升高后降低,塑性和电导率趋于降低;相对高能球磨、分子水平法等单一混粉工艺而言,两步法制备的Cu-1.0%CNTs复合材料综合性能更优,其电导率为51.7 MS/m(89.1%IACS),维氏硬度为1130 MPa,抗拉强度为279 MPa,断后伸长率为9.8%。     

A critical review of diamond like carbon coating for wear resistance applications

In recent years innovation in carbon based materials have encouraged both researchers as well as industrialists to develop materials/composites with improved tribological properties. Researchers have been fascinated to develop diamond like carbon (DLC) or carbon nanotubes (CNTs) reinforced coatings to their good corrosion resistance, excellent wear resistance, good adhesion strength, and self -lubricious nature. The present review article is mainly focused on various techniques employed in order to process DLC/CNTs coatings as well as provide a summary of DLC/CNTs deposition on different substrates. The present study includes major types, properties and tribological behavior of carbon based materials and mechanisms involved in coating deposition. The study also discusses that deposition of DLC/CNTs coatings on the substrate materials enhances the wear, corrosion and mechanical properties of the substrate.     

Effects of Carbon Allotropic Forms on Microstructure and Thermal Properties of Cu-C Composites Produced by SPS

Combination of extreme service conditions and complex thermomechanical loadings, e.g., in electronics or power industry, requires using advanced materials with unique properties. Dissipation of heat generated during the operation of high-power electronic elements is crucial from the point of view of their efficiency. Good cooling conditions can be guaranteed, for instance, with materials of very high thermal conductivity and low thermal expansion coefficient, and by designing the heat dissipation system in an accurate manner. Conventional materials such as silver, copper, or their alloys, often fail to meet such severe requirements. This paper discusses the results of investigations connected with Cu-C (multiwall carbon nanotubes (MWNTs), graphene nanopowder (GNP), or thermally reduced graphene oxide (RGO)) composites, produced using the spark plasma sintering technique. The obtained composites are characterized by uniform distribution of a carbon phase and high relative density. Compared with pure copper, developed materials are characterized by similar thermal conductivity and much lower values of thermal expansion coefficient. The most promising materials to use as heat dissipation elements seems to be copper-based composites reinforced by carbon nanotubes (CNTs) and GNP.     

挤压熔体浸渗法制备金属涂覆碳纤维增强铝基复合材料的润湿性和力学性能改善

为了改善碳纤维与铝基体之间界面的润湿性和结合性能,采用挤压熔体浸渗法制备镍和铜涂覆碳纤维增强铝基复合材料,对两种不同涂层碳纤维增强铝基复合材料的界面润湿性、显微组织和力学性能进行比较和研究.显微组织结构分析表明,与无涂层碳纤维增强铝基复合材料相比,在相同的浸渗工艺条件下,在碳纤维表面涂覆两种金属均可以显著改善碳纤维与铝...     

The effect of sintering temperature on some properties of Cu-SiC composite

Copper matrix composites reinforced with 1 wt.%, 2 wt.%, 3 wt.% and 5 wt.% SiC particles were fabricated by powder metallurgy method. Cu and Cu-SiC powder mixtures were compacted with a compressive force of 280 MPa and sintered in an open atmospheric furnace at 900-950 °C for 2 h. Within the furnace compacted samples were embedding into the graphite powder. The presence of Cu and SiC components in composites was verified by XRD analysis. Optical and SEM studies showed that Cu-SiC composites have a uniform microstructure in which silicon carbide particles are distributed uniformly in the copper matrix. The results of the study on mechanical and electrical conductivity properties of Cu-SiC composites indicated that with increasing SiC content (wt.%), hardness increased, but relative density and electrical conductivity decreased. The highest electrical conductivity of 98.8% IACS and relative density of 98.2% were obtained for the Cu-1 wt.%SiC composite sintered at 900 °C and this temperature was defined as the optimum sintering temperature.