共查询到20条相似文献,搜索用时 0 毫秒
1.
Katsuyoshi Kondoh Thotsaphon Threrujirapapong Hisashi Imai Junko Umeda Bunshi Fugetsu 《Composites Science and Technology》2009,69(7-8):1077-1081
By using pure titanium powder coated with un-bundled multi-wall carbon nanotubes (MWCNTs) via wet process, powder metallurgy (P/M) titanium matrix composite (TMC) reinforced with the CNTs was prepared by spark plasma sintering (SPS) and subsequently hot extrusion process. The microstructure and mechanical properties of P/M pure titanium and reinforced with CNTs were evaluated. The distribution of CNTs and in situ formed titanium carbide (TiC) compounds during sintering was investigated by optical and scanning electron microscopy (SEM) equipped with EDS analyzer. The mechanical properties of TMC were significantly improved by the additive of CNTs. For example, when employing the pure titanium composite powder coated with CNTs of 0.35 mass%, the increase of tensile strength and yield stress of the extruded TMC was 157 MPa and 169 MPa, respectively, compared to those of extruded titanium materials with no CNT additive. Fractured surfaces of tensile specimens were analyzed by SEM, and the uniform distribution of CNTs and TiC particles, being effective for the dispersion strengthening, at the surface of the TMC were obviously observed. 相似文献
2.
碳纳米管(CNTs)具有极高的力学性能、优异的导电和导热性能,被视为理想的复合材料增强相。CNTs增强复合材料已成为一个极为重要的研究领域。然而,由于CNTs与金属基体间相容性、增强体空间分布难以控制、CNTs本身载流量高而电导率相对较低等,CNTs增强金属基复合材料尚未展现出对金属基体电学性能的显著提升,或者无法有效兼顾电学性能和力学性能,整体研究仍处于起步阶段。鉴于此,从预处理、制备方法和电学机制分析等方面概述了CNTs增强金属基复合材料电学性能的研究现状,并展望了该领域的未来发展趋势。 相似文献
3.
《材料科学技术学报》2017,(10)
In-situ TiC and remained multi-walled carbon nanotubes(MWCNTs) reinforced Ti composites were synthesized using vacuum hot-press sintering and hot rolling. The effect of weight fraction of MWCNTs on microstructural evolution and mechanical properties of the Ti composites was investigated. The results indicated that both proportion and particle size of TiC increased in proportion to MWCNTs content, which resulted in different matrix microstructure, and the grains were obviously refined after rolling deformation. The hardness tests indicated that MWCNTs addition could make the composites harden, and 18.4%improvement in hardness was obtained after hot rolling. The significant improvement in both strength and hardness could be attributed to grain refinement, solid solution strengthening of carbon and dispersion strengthening of TiC particles and remained MWCNTs. A good combination of strength and ductility were achieved in Ti–1 wt% MWCNTs composites, which were in accordance with the uniform distribution of smaller-sized TiC particles in Ti matrix. 相似文献
4.
Mg matrix composites reinforced by carbon nanotubes (CNTs)-Al2O3 mixture, which was synthesized by in situ growing CNTs over Al2O3 particles through chemical vapor deposition (CVD) using Ni catalyst, were fabricated by means of powder metallurgy process, followed by hot-extrusion. By controlling synthesis conditions, the as-grown CNTs over Al2O3 particles possessed high degree of graphitization, ideal morphology, higher purity and homogeneous dispersion. Due to the ‘vehicle’ carrying effect of micrometer-level A2O3, CNTs were easy to be homogeneously dispersed in Mg matrix under moderate ball milling. Meanwhile, Al2O3 particles as catalyst carriers, together with CNTs, play the roles of synergistic reinforcements in Mg matrix. Consequently, the Mg matrix composites reinforced by CNTs-Al2O3 mixture exhibited remarkable mechanical properties. 相似文献
5.
Four Ti MMCs have been tested in transverse tension, at ambient temperature and 600 °C. Generally, mechanical properties are reduced compared to monolithic Ti alloys. Transverse Young's modulus is, however, higher than in monolithic alloys, as a result of constraint of the matrix by the fibres.MMC proportional limits are associated with the onset of interfacial failure. Fibre coating cracking and longitudinal fibre splitting may also contribute to MMC yield and the associated acoustic emission peak. The fibre/matrix interface in IMI 834/SM1140+ appears to be weaker than in the other MMCs, resulting in a lower proportional limit and less acoustic emission. Final failure of the MMCs is generally via ductile shearing of matrix ligaments. The exception to this is IMI 834/SM1140+ in which the matrix fails in a brittle manner. This causes poor transverse tensile strength and failure strain in this MMC.A model to predict the MMC proportional limit, previously proposed by Jansson et al., has been modified to take account of the tensile strength of the fibre/matrix interface. The model previously used by Jansson et al. to predict the transverse tensile strength is acceptably accurate provided that the area fraction of matrix appearing on fracture surfaces is accurately determined. 相似文献
6.
In this investigation, carbon nanotube (CNT) reinforced aluminum composites were prepared by the molecular-level mixing process using copper coated CNTs. The mixing of CNTs was accomplished by ultrasonic mixing and ball milling. Electroless Cu-coated CNTs were used to enhance the interfacial bonding between CNTs and aluminum. Scanning electron microscope analysis revealed the homogenous dispersion of Cu-coated CNTs in the composite samples compared with the uncoated CNTs. The samples were pressureless sintered under vacuum followed by hot rolling to promote the uniform microstructure and dispersion of CNTs. In 1.0 wt.% uncoated and Cu-coated CNT/Al composites, compared to pure Al, the microhardness increased by 44% and 103%, respectively. As compared to the pure Al, for 1.0 wt.% uncoated CNT/Al composite, increase in yield strength and ultimate tensile strength was estimated about 58% and 62%, respectively. However, in case of 1.0 wt.% Cu-coated CNT/Al composite, yield strength and ultimate tensile strength were increased significantly about 121% and 107%, respectively. 相似文献
7.
Paloma Hidalgo-Manrique Shaojiu Yan Fei Lin Qihu Hong Ian A. Kinloch Xiang Chen Robert J. Young Xiaoyan Zhang Shenglong Dai 《Journal of Materials Science》2017,52(23):13466-13477
Aluminium (Al) matrix composites reinforced with either 0.5 wt% graphene oxide (GO) or 0.5 wt% carbon nanotubes (CNTs) were hot extruded from ball-milled powders. A control, pure Al bar was also fabricated. Microstructural examination, including Raman mapping, showed a relatively poor dispersion of the carbon nanomaterials within the Al matrix, particularly in the case of the CNTs. Consequently, while the mean grain size of the Al matrix remains invariant with the addition of CNTs, the Al/GO composite exhibits reduced grain size compared to pure Al due to the pinning effect of the reinforcement. Moreover, the addition of both carbonaceous materials resulted in a slight decrease in the typical extrusion duplex <111> + <100> fibre texture intensity. This weakening of the texture was more pronounced in the Al/GO composite, partly due to the pinning effect of the reinforcement. In agreement with their relative mean grain sizes, the Al/GO composite shows an improved mechanical performance over pure Al. Despite the similarity of the mean grain sizes, the Al/CNT composite displays comparable hardness and a decreased compressive yield stress relative to the pure Al. In the absence of chemical reactions at the interfaces, this was attributed to a low efficiency of load transfer from the Al matrix to the reinforcement resulting from the large extent of agglomeration of CNTs. 相似文献
8.
Joanna LipeckaMariusz Andrzejczuk Ma?gorzata Lewandowska Jolanta Janczak-RuschKrzysztof J. Kurzyd?owski 《Composites Science and Technology》2011,71(16):1881-1885
The effect of carbon nanotubes on the thermal stability of ultrafine grained aluminium alloy processed by the consolidation of nano-powders obtained by mechanical alloying was evaluated via measurements of grain size and mechanical property changes upon annealing at various temperatures. It was found that the grain size of the samples containing carbon nanotubes is stable up to high temperatures and even after annealing at 450 °C (0.7Tm) no evident grain growth was observed. The limited grain boundary migration was attributed to the presence of entangled networks of carbon nanotubes located at grain boundaries and to the formation of nanoscale particles of aluminium carbide Al4C3. It was also revealed that carbon nanotubes decompose at a relatively low temperature of 450 °C and form fine Al4C3 precipitates. This transformation does not significantly affect the mechanical properties due to the nanoscale size of the carbides. 相似文献
9.
On the microstructure of single wall carbon nanotubes reinforced ceramic matrix composites 总被引:1,自引:1,他引:0
E. Zapata-Solvas D. Gómez-García A. Domínguez-Rodríguez 《Journal of Materials Science》2010,45(9):2258-2263
A microstructural modelling of the microstructure in single wall carbon nanotubes reinforced alumina ceramics has been developed.
The model accounts for the main microstructural features, being quite useful to describe the carbon nanotube distribution
along the ceramic matrix. The microstructural analysis derived from this model is found to give a deeper insight into the
high-temperature creep of these composites. 相似文献
10.
11.
The matrix grain size plays a dual role in metal matrix composites (MMCs). Contrary to enhance the strength of matrix, grain refinement can weaken the thermal expansion mismatch strengthening induced by the reinforcement. In this article, a dislocation density based model is developed to describe the factors affecting the strengthening mechanisms in Carbon nanotube (CNT)-reinforced MMCs with different matrix grain sizes. Two kinds of thermal expansion mismatch strengthening mechanisms are considered, i.e., geometrically necessary dislocations (GNDs) are distributed in entire matrix and GNDs are limited in dislocation punched zones (DPZs). In addition, comparisons between the predictions and some available experimental results are also performed. 相似文献
12.
In this paper, either graphite (Gr) or carbon nanotubes (CNTs), or both of them were incorporated into carbon fabric reinforced phenolic (CFRP) composites, preparing by a dip-coating and heat molding process, the tribological properties of the resulting composites were investigated using a block-on-ring arrangement. The worn surfaces were observed by scanning electron microscope to understand the mechanism. Experimental results showed that the optimal Gr was more beneficial than CNTs in improving the tribological properties of the CFRP composites when they were singly incorporated. It is well worth noting that the friction and wear behavior of the CNTs-filled CFRP composites were improved further when Gr was added, indicating that there is a synergistic effect between them. Tribological tests under different sliding conditions revealed that the Gr and CNTs-filled CFRP composites seemed to be the most suitable for tribological applications under higher sliding speed and load, and oil lubrication. 相似文献
13.
Ceramic matrix composites containing carbon nanotubes 总被引:1,自引:0,他引:1
Due to the remarkable physical and mechanical properties of individual, perfect carbon nanotubes (CNTs), they are considered
to be one of the most promising new reinforcements for structural composites. Their impressive electrical and thermal properties
also suggest opportunities for multifunctional applications. In the context of inorganic matrix composites, researchers have
particularly focussed on CNTs as toughening elements to overcome the intrinsic brittleness of the ceramic or glass material.
Although there are now a number of studies published in the literature, these inorganic systems have received much less attention
than CNT/polymer matrix composites. This paper reviews the current status of the research and development of CNT-loaded ceramic
matrix composite (CMC) materials. It includes a summary of the key issues related to the optimisation of CNT-based composites,
with particular reference to brittle matrices and provides an overview of the processing techniques developed to optimise
dispersion quality, interfaces, and density. The properties of the various composite systems are discussed, with an emphasis
on toughness; a comprehensive comparative summary is provided, together with a discussion of the possible toughening mechanism
that may operate. Last, a range of potential applications are discussed, concluding with a discussion of the scope for future
developments in the field. 相似文献
14.
Hiroyuki Fukuda Katsuyoshi KondohJunko Umeda Bunshi Fugetsu 《Composites Science and Technology》2011,71(5):705-709
Magnesium containing 6 wt.% aluminum alloy composites reinforced with carbon nanotubes were fabricated with powder metallurgy based wet-processing. Yield stress and tensile strength were successfully improved by the addition of carbon nanotubes. Field emission-transmission electron microscopy microstructural analysis clarified that needle-like ternary carbides of Al2MgC2 were synthesized at some interfaces between magnesium matrix and carbon nanotubes, and the other interfaces were clean without any other materials or defects. Tensile loading transfer from magnesium matrix to carbon nanotubes was effectively strengthened by both the production of Al2MgC2 compounds and the clean interface between magnesium matrix and carbon nanotubes. 相似文献
15.
Jianwei ZhangDazhi Jiang 《Composites Science and Technology》2011,71(4):466-470
A modified method for interconnecting multi-walled carbon nanotubes (MWCNTs) was put forward. And interconnected MWCNTs by reaction of acyl chloride and amino groups were obtained. Scanning electron microscopy shows that hetero-junctions of MWCNTs with different morphologies were formed. Then specimens of pristine MWCNTs, chemically functionalized MWCNTs and interconnected MWCNTs reinforced epoxy resin composites were fabricated by cast moulding. Tensile properties and fracture surfaces of the specimens were investigated. The results show that, compared with pristine MWCNTs and chemically functionalized MWCNTs, the chemically interconnected MWCNTs improved the fracture strain and therefore the toughness of the composites significantly. 相似文献
16.
17.
Kaijie Lin Yamei Fang Dongdong Gu Qing Ge Jie Zhuang Lixia Xi 《Advanced Powder Technology》2021,32(5):1426-1437
Graphene is an attractive reinforcement in enhancing performances of titanium matrix composites (TMCs). However, the fabrication of graphene reinforced TMCs components is challenging to conventional manufacturing technologies. Selective laser melting (SLM) shows great potential in fabrication of TMCs components. In this study, SLM was employed to fabricate graphene reinforced TMCs, and the effects of ball milling time on properties of composite powder and resultant SLM formability were investigated. The morphologies, chemical composition, flowability and phase constitute of composite powder were evaluated by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), Hall flowmeter and X-ray diffraction (XRD), respectively. The structure of graphene in composite powder was assessed by Raman spectroscopy. The formability of SLM scanning-track using different composite powder was also studied. The results showed that the composite powder, milled for 5 h, possessed good sphericity, good flowability and well-dispersion of graphene. Finally, the SLM-processed graphene reinforced TMCs, using the optimized composite powder, exhibited higher microhardness of 432.03 HV0.2, higher tensile strength of 1276 MPa and lower coefficient of friction of 0.3453 than that of the SLM-processed TC4, revealing the great improvement in mechanical performance of the SLM-processed TMCs by adding graphene. 相似文献
18.
This study compares the mechanical and thermal properties of glassy and rubbery epoxy–matrix composites reinforced with 1 and 4 wt.% single-walled carbon nanotubes (SWCNTs), multi-walled carbon nanotubes (MWCNTs), graphite, and carbon nanofibers (CNFs). The tensile modulus of most glassy composites was higher than that of the epoxy and increased with higher filler concentration and 4% graphite/epoxy and 4% SWCNT/epoxy exhibited approximately the same highest tensile modulus. The elongation of glassy composites was significantly lower than that of the epoxy and decreased with increasing filler loading. Most rubbery composites showed a higher tensile modulus and elongation than the epoxy and the modulus increased with rising filler content and 4% SWCNT/epoxy showed the highest tensile modulus and tensile strength. In the rubbery regime, glassy and rubbery composites displayed a higher storage modulus than the corresponding epoxy and 4 wt.% SWCNT/epoxy composites showed a 300% improvement in storage modulus compared to the epoxy. 相似文献
19.
《材料与设计》2015
The influence of various synthesis techniques on the dispersion and evolution of multi-walled carbon nanotubes (MWCNTs) in titanium (Ti) metal matrix composites (TMCs) prepared via powder metallurgy routes has been investigated. The synthesis techniques included sonication, high energy ball milling (HEBM), cold compaction, high temperature vacuum sintering and spark plasma sintering (SPS). Powder mixtures of Ti and MWCNTs (0.5 wt.%) were processed by HEBM in two batches: (i) ball milling of the mixtures (Batch 1) and (ii) ball milling of Ti powder alone, followed by a further ball milling with sonicated MWCNTs (Batch 2). Both batches of the powder mixtures were pressed at 40 MPa into green compacts and then sintered in vacuum. Batch 2 powder mixtures were also consolidated using SPS. The crystallinity and sp2 carbon network of the MWCNTs were characterized through analyzing the characteristic Raman peak ratio (ID/IG) of each processed sample. X-ray diffraction (XRD) was used for phase identification. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to study the morphology of the MWCNTs in the powder mixtures. The evolution of MWCNTs during the fabrication process and mechanical properties of the sintered compacts were discussed in conjunction with the formation of nano-crystalline TiC. 相似文献
20.
A. L. FILHO H. ATKINSON H. JONES E. DE LOS RIOS S. KING 《Journal of Materials Science》1998,33(23):5517-5533
Metal reinforced Metal Matrix Composites (MMMCs) made by combining an aluminium alloy matrix with stainless steel reinforcing wires are potentially cheaper and tougher than continuous fibre ceramic reinforced Metal Matrix Composites (MMCs). Although they do not give as great enhancements in stiffness and strength, worthwhile gains are achieved. Such MMMCs can be produced by Hot Isostatic Pressing (HIPping), which reduces interfacial reactions in comparison with liquid metal routes. Here, stainless steel (316L) and commercial purity aluminium wires were used to make bundles which were inserted into mild steel cans for HIPping at 525 °C/120 min/100 MPa. Some stainless steel wires were pre-coated with A17Si, to examine the effect of coatings on mechanical properties. Specimens were evaluated in terms of their tensile and fatigue properties. During HIPping, cans collapsed anisotropically to give different cross-section shapes, and for larger diameter cans, there was also some longitudinal twisting. Wires tended to be better aligned after HIPping in the smaller diameter cans, which produced material having higher modulus and UTS. Higher volume fractions of reinforcement tend to give better fatigue properties. Composites with coated stainless steel wires gave higher composite elongation to failure than uncoated wires. Both uncoated and coated wires failed by fatigue during fatigue testing of the composite. This contrasts with ceramic reinforced MMCs where the fibres fracture at weak points and then pull out of the matrix. 相似文献