al sic gr metal matrix composites

... material wastage) and finally, the control of tungsten grain growth within the tungsten matrix There has been great interest with regards to grain size on the effect of metal components since Hall ... within the final composite was also in question Despite the technological capability at this juncture, tungsten-copper metal matrix composites never really found head way as a commercial mainstay ... SYMBOLS ko Grain growth equation constant R Universal gas constant L Lorenz number g Acceleration due to gravity G Gravitational constant Re Reynold’s number Z Infiltration number Dfinal Final grain...

Ngày tải lên: 14/09/2015, 08:45

... FIGURES Fig 2.1 Qualitative analysis of the interphase intermetallic-aluminium alloy Top, atomized intermetallic; bottom, mechanical alloying (MA) intermetallic (Torralba et al. , 2002) 17 Fig ... continuous metallic host material, it is called metal matrix composite (MMC) Particle-reinforced metal matrix composites have been extensively used in mechanical engineering as structural and/or ... 6061/ Al2 O3 metal matrix composites, Das et al (1997) found that the elastic moduli of both the 16 Fig 2.1 Qualitative analysis of the interphase intermetallic-aluminium alloy Top, atomized intermetallic;...

Ngày tải lên: 09/09/2015, 08:12

... 1.1 Metal matrix composites – overview 1.2 Numerical studies on metal matrix composites 1.2.1 Metal matrix composite systems 1.2.2 Influence of various microstructural features on mechanical properties ... this study shall be presented 1.1 Metal matrix composites – overview A metal matrix composite (MMC) is a composite material with a reinforcement phase dispersed within a continuous metallic host, ... This page is intentionally left blank xxiv 1.0 Introduction This chapter gives an overview of metal matrix composites (MMCs) and metal matrix nanocomposites (MMNCs), the numerical studies which have...

Ngày tải lên: 09/09/2015, 18:53

... Fibre-reinforced metal- matrix composites, Composites, 16, pp 187-206 1985 Luo, A Processing, microstructure, and mechanical behaviour of cast Mg metal matrix composites, Metall Trans A, 26, pp ... Reinforced Metal Matrix Composites, Compos Sci Tech., 61: 1057–1063 17 Ramakrishnan, N (1996) An Analytical Study on Strengthening of Particulate Reinforced Metal Matrix Composites, Acta Metall., ... strengthened by SiC nanoparticles, Mater Sci Eng A, 298, pp 193-199 2001 17 Tiny tubes boost for metal matrix composites, Metal Powder Report, 59, pp 40-43 2004 Advanced Lightweight Metal Based Composites...

Ngày tải lên: 12/09/2015, 08:19

... dielectric core, metal shell and host matrices in the core-shell composites, we have derived an analytical expression for the polarization of individual metal shell spherical and cylindrical inclusions ... conventional Rayleigh approximation The electric potential distribution of the composites having dielectric core, metal shell and host matrices are systematically calculated As such metal/ dielectric ... (RTFM) Recent theoretical and experimental studies in DMS materials revealed RTFM for wide band gap materials such as GaN and ZnO for TM doping These metals have partially filled 3d states and...

Ngày tải lên: 14/08/2017, 15:55

... Classification based on matrix type: a) polymer -matrix composites (PMCs) or fibre-reinforced plastics (FRPs), b) metal- matrix composites (MMCs), c) ceramic -matrix composites (CMCs); Sandwich composites with ... because I wanted real responsibili� I joined MITAS because I wanted real responsibili� Real work International Internationa al opportunities �ree wo work or placements �e Graduate Programme for Engineers ... Fatigue and wear 4.9 Differential scanning calorimetry 4.10 Dynamic mechanical thermal analysis 4.11 Environmental effects on properties 4.12 Non destructive evaluation 4.13 Self-assessment questions...

Ngày tải lên: 16/12/2017, 07:31

... the laws of electromagnetics All numerical techniques involve discretization In most traditional approaches the physics is first modeled as a differential or integral equation, with continuous ... Thermal and Particle Diffusion 87 Introduction 87 Spatial Discretizations and Electrical Networks for Thermal and Particle Diffusion 88 TLM Algorithm for a 1-D Link-line Nodal ... of Mechanical Engineering is also the largest such department in the country, enjoying a worldwide reputation for teaching and research) In addition to both analytical and numerical analysis of...

Ngày tải lên: 05/05/2014, 17:21

... Nanocomposites 76 Fe-Based Nanocomposites 77 References 80 3.1 3.1.1 3.2 3.2.1 3.2.2 3.3 Physical Properties of Carbon Nanotube Metal Nanocomposites Background 89 Thermal Response of Metal- Matrix ... Metal- Matrix Microcomposites 91 Thermal Behavior of Metal- CNT Nanocomposites 93 Aluminum-Based Nanocomposites 93 Tin-Based Nanosolder 95 Electrical Behavior of Metal- CNT Nanocomposites 98 References ... for polymer-, metal- or ceramic -matrix composites to obtain light-weight structural materials with enhanced mechanical, electrical and thermal properties [6–8] Composite materials with at least...

Ngày tải lên: 04/06/2014, 15:04

... nanostructures such as metal nanoparticles [NPs] to modify the barrier height at metal -SiC interfaces and to alter fundamental SiC device properties by controlling the size of the metal NPs Previous ... are basically Ni /SiC contacts embedded with the metal NPs to the 4H -SiC substrate Figure shows the fabricated samples with metal NPs: Ni /SiC contacts embedded with the Au-NPs (NP-1) and Ni /SiC ... analog SrTiO3 metal insulator metal capacitors IEEE Trans Electron Devices 2007, 28:694-696 19 Silvaco International: Atlas User’s Manual Santa Clara CA; 1998 20 Rhoderick EH, Williams RH: Metal Semiconductor...

Ngày tải lên: 20/06/2014, 20:20

... potential barrier at the interface of AZO and p-type a -SiC: H is made gradual by inserting a buffer layer A few-nanometer-thick nanocrystalline silicon buffer layer between the AZO and a -SiC: H ... effect of potential barrier at the interface is almost negligible Although the cell with the AZO/p+ a -SiC: H /p-type a -SiC: H front interface structure does not show the effect of potential barrier at ... energy band diagram changes much First, the barrier height is reduced The bandgap of the nanocrystalline silicon is smaller than a -SiC: H, indicating that both the optical and electrical properties...

Ngày tải lên: 20/06/2014, 20:20

... in 3C -SiC cause a localized lowering of the resistance through the layer [16] As a consequence, the crystalline quality of the 3C -SiC epilayer is pivotal for good device operation The micrographs ... high-temperature annealing on the structural and electrical properties of Pt/3C -SiC is ambiguous In this study, XRD analysis (not reported here) showed that the Pt2Si phase was formed already after annealing ... characterized by local low-barrier patches, ultimately leading to an increase of the leakage current [26] Conclusion Nanoscale electrical and structural characterization of metal/ 3C -SiC interfaces...

Ngày tải lên: 21/06/2014, 05:20

... potential barrier at the interface of AZO and p-type a -SiC: H is made gradual by inserting a buffer layer A few-nanometer-thick nanocrystalline silicon buffer layer between the AZO and a -SiC: H ... effect of potential barrier at the interface is almost negligible Although the cell with the AZO/p+ a -SiC: H /p-type a -SiC: H front interface structure does not show the effect of potential barrier at ... energy band diagram changes much First, the barrier height is reduced The bandgap of the nanocrystalline silicon is smaller than a -SiC: H, indicating that both the optical and electrical properties...

Ngày tải lên: 21/06/2014, 17:20

... polymer–polyoxometalate composites Different conducting polymers–polyoxometalate composites have been prepared by both chemical and electrochemical routes and used for photoelectrochemical and energy ... [36] The synthesis of metal nanoparticle–polyoxometalate composites based photo-catalytic reduction has been pioneered by Papaconstantinou et al [31] Wherein, polyoxometalates (SiW12O4-, PW12O3-) ... as reducing agent for the metal (Ag and Au) ions to form metal nanoparticles The high-resolution transmission electron microscopic analysis revealed formation of metal embedded polymer nanostructures...

Ngày tải lên: 22/06/2014, 06:20

... solution-processed graphene is the main ingredient used for the preparation of composites with Metal Organic Framework (MOF) 1.3 Reactions of Graphene Graphene can be functionalized covalently or non-covalently ... functional groups present on the GO surface A related study with HKUST-1 and unfunctionalised graphite reveals only the formation of physical mixtures The relative orientation of metal coordination ... of metal organic framework By reacting the pyridine-functionalized graphene with iron-porphyrin, a graphene-metalloporphyrin MOF was synthesized This composite was used as catalytic material...

Ngày tải lên: 10/09/2015, 09:06

... resultant diffractogram is formed by addition of the individual patterns From X-ray diffraction, a wealth of structural, physical and chemical information about the material investigated can ... non-destructive technique that reveals detailed information about the chemical composition and crystallographic structure of a substance In materials with a crystalline structure, X-rays scattered ... myriad of application, from catalyst characterization to fundamental physics of adsorbate ionization XPS measures the elemental composition, empirical formula, chemical state and electronic state...

Ngày tải lên: 10/09/2015, 09:06

... and drain metal electrodes, the system can be considered as a metaldielectric -metal system The presence of graphene may change the dielectric breakdown strength of the material, or allow Frenkel-Poole ... the structural analysis, a growth mechanism of MOF/BFG nanowires is proposed, as shown in Figure 3.7 Since the main functional groups on the basal planes of BFG are phenyl carboxylic groups, it ... among all planes This suggests that the high concentration of carboxylic functional groups on BFG has influenced the growth direction in the MOF crystals along the [220] direction due to strong metal- carboxylate...

Ngày tải lên: 10/09/2015, 09:06

... difference in structure between graphene-metalloporphyrin MOF and metalloporphyrin MOF without graphene This is important for understanding how graphene influences the crystallization of the MOF, and ... reused catalysts largely resemble that of as-prepared (G-dye 10 wt % FeP)n MOF The presence of almost all functional groups in the catalyst after reaction attests to the stability of catalyst Figure ... dye-functionalized r-GO sheets into the metalloporphyrin network Our studies reveal that functionalized r-GO sheets can influence the crystallization process of MOF and promote the catalytic properties...

Ngày tải lên: 10/09/2015, 09:06

... reactions in alkaline media In this work we employed reduced GO (r-GO) sheets that are functionalized on either side of the basal plane with pyridine ligands, these function as struts to link metalloporphyrin ... electrochemical process, we compared its electrocatalytic performance with (i) unfunctionalised graphene; (ii) (Fe-P)n MOF; (iii) (G 50 wt % -FeP)n MOF, which is a composite between unfunctionalised graphene ... of nitrogen in carbon materials, especially in the form of the pyridinium moieties, is critical in enhancing the electrocatalytic activity for ORR.11 This improved catalytic performance is ascribed...

Ngày tải lên: 10/09/2015, 09:06

... GO intercalated Cu-MOF composite as a tri-functional catalyst for ORR, OER and HER The GO-intercalated composites exhibit smaller overpotentials and higher current for all electrocatalytic reactions ... for a non-Pt catalyst that can rival the performance of Pt catalyst.5 Reduced graphene oxide (GO) based materials have been studied extensively as electrode materials and catalyst supports due ... Moore, R B.; Yi, B Physical Chemistry Chemical Physics 2011, 13, 15384 (9) Dreyer, D R.; Park, S.; Bielawski, C W.; Ruoff, R S Chemical Society Reviews 2010, 39, 228 (10) Allendorf, M D.; Schwartzberg,...

Ngày tải lên: 10/09/2015, 09:06

... polymermetal systems since such incorporation of metals is known to enhance conductivity of the polymer, be applied as novel catalysts for a great number of synthetic reactions and allow metal- ligand ... transfer to metal ions in solution causing metals to be deposited at the surface The deposition of such metals renders the polymer surface active towards further metal deposition from conventional electroless ... Cromack et al. , 1989; Tang et al. , 1989; Andreatta et al. , 1988) The conventional methods to prepare polyaniline are chemical and electrochemical polymerization The chemical synthesis is usually carried...

Ngày tải lên: 15/09/2015, 22:25