metallurgy materials and mechanical properties

... change in environment and responding without need for a microprocessor 2 A device has both gas sensing and actuating function by integration of semiconducting oxide and piezoelectric thin ... resistant • Chemically inert • Abrasion resistant Wide band gap semiconductor/insulator Photo Electro-chemical Etching - PEC • materials versatility e.g Si, SiC, Ge, GaAs, GaN, etc • precise ... NO2 NH3 Feuchte CO NO2kl H2 time / h 100k Temp:360C, H 2 , CO, NH 3 (10, 50 and 100 ppm), NO 2 (0.2, 0.4, and 2 ppm) ZnO(Ar:O2=7:3) 1 [ Pfad: \ alpha missy Messungen messplatz_1 ] M Jägle

Ngày tải lên: 11/08/2014, 14:20

... Trang 83.225 9 Colors Produced by Chromium Above: alexandrite, emerald, and ruby Center: carbonate, chloride, oxide Below: potassium chromate and ammonium dichromate © H.L Tuller, 2001 Electron ... five 3d orbitals in a tetrahedral and an octahedral ligand field Note: hen the element is a mid-gap dopant, transitions within this element lead to absorption and/or emission via luminescence ... chromium atom (A) and a trivalent chromium ion (B) Chromium Electronic Structure © H.L Tuller, 2001 Trang 93.225 11 Interaction of the d orbitals of a central ion with six ligands in an octahedral

Ngày tải lên: 11/08/2014, 14:20

... alter the properties of bulk nc materials 2.3 Mechanical behaviours of nanocrystalline materials For understanding of the mechanical properties of nanophase materials in general, a quantitative ... atoms in these materials is located in the grain boundaries (Fig 2.3) and thus the material exhibits enhanced combinations of physical, mechanical, and magnetic properties compared to materials with ... represent a new generation of advanced materials exhibiting unique properties due to the size and interface effects [9-18] Nc materials are single-phase or multi-phase materials, the crystal size of

Ngày tải lên: 14/09/2015, 14:10

... operating at 40 kV and 30 mA was carried out for structural examination of MMed powders and MMed powders after annealing at 500°C and 1250°C (designated hereafter as MMed, MMed-500 and MMed-1250 samples ... melting point and asymmetric structure of pyrazine, it is unstable under thermal treatment and/or mechanical activation [23] Pyrazine therefore decomposed to some extent after 40h of milling and a certain ... in 20h and 30h-MMed-500 samples After annealing at 1250°C, AlN was found to form in both 20h and 30h-MMed powders In addition to AlN formation, oxide and carbide were detected from Al2O3 and Al4C3

Ngày tải lên: 14/09/2015, 14:10

... the excellent mechanical properties Inherent deficiencies such as low stiffness, high wear rate, and high chemical reactivity, loss of mechanical strength at high temperature and creep resistance ... in-situ AlN formed reinforcement were synthesized for milling durations up to 40h and their physical and mechanical properties were accessed The contribution of texture developed during extrusion ... control agent, stearic acid and powder handling atmosphere can also be observed from the weak MgO (200) peak and MgH2 (211) peak, especially at milling durations of 20h and longer Al12Mg17 peaks

Ngày tải lên: 14/09/2015, 14:10

... as deformation mechanism of nc metallic materials experimentally by mechanical testing and theoretically by simulation models [21-26] However, Jain and Christman [27] suggested that nc Fe alloy ... dependence nature of strength in nanostructured Mg composite materials This phenomenon is one of the unique properties of nanostructured materials and it has been reported by previous studies [29] This ... 3.33x10-3 s-1, 3.33x10-4 s-1 and 3.33x10-5 s-1 are shown in Fig 5.5 and the detailed results are given in Table 5.2 (c) 20h, (d) 30h and (e) 40h Trang 9Table 5.2 Yield strength and % elongation of pure

Ngày tải lên: 14/09/2015, 14:11

... 6.4) and GBS model (equation 6.6) Similar results were reported for the creep behavior of nanostructured Mg alloys [30] and nanocrystalline Cu, Pd, and Al-Zr [31] The existing Coble creep and ... 60, 80, 100, 120 and 130 MPa with dwelling time of 2 hours 6.3 Results and discussion 6.3.1 Creep behaviors Table 6.1 Creep strain rate (s-1) at various applied stresses and temperatures Trang ... relationship between  and  is lost and appears to be replaced by a relationship of the form  -0 where 0 is a threshold stress below which creep does not occur and the effective applied

Ngày tải lên: 14/09/2015, 14:11

... characterizethe mechanical properties of TCO films and most of them were focused on n-typeTCOs Report on mechanical properties of p-type TCOs is rare, if any In par-ticular, no report on the mechanical properties ... oxide (TCO) materials,especially on Cu-Al-O Sections 2.3 and 2.4 introduce the contemporary research on the optical and mechanical properties of TCO materials Since reports on both of the properties ... optical and mechanical properties of Cu-Al-O films are discussedin the following two chapters, namely chapter 4 and chapter 5 In the final chapter, an overall summary of the current work and suggestion

Ngày tải lên: 27/11/2015, 12:13

... mainly on their mineralogical composition and physico-sintering properties (Bordia & Camacho-Montes 2012) The mineralogical and physical properties and mechanical strength of the fired clay bricks ... important physico-sintering properties of all types bricks while the compressive strength is one of the important mechanical properties All these physico-sintering and mechanical properties are reported ... density and apparent porosity) and mechanical (i.e., flexural or compressive strength) properties act as the quality control and durability of the clay bricks, which ultimately depend on the phase and

Ngày tải lên: 13/01/2020, 13:00

... low-carbon boiler steel and the chemical compo-sition (wt%) of the work material is given in Table 1 The mechanical properties of the candidate metal such as tensile and impact properties are tabulated ... University. Trang 2SA516 grade 70Mechanical properties Metallurgical properties strength The yield strength and ultimate tensile strength of the welded joints were 338 MPa and 549 MPa, respectively, ... for mechanical properties at the selected welding parameters (Laser power of 2000 W and welding speed of 400 mm/min).Table 4also shows the repro-ducibility analysis of tensile and impact properties

Ngày tải lên: 13/01/2020, 13:25

... switching off and on the light Mechanical properties of the resultant thin films The indentation, scratch, and imaging techniques were employed for evaluation of mechanical and tribological properties ... best materials for multifunctional materials thin film The main advantages for these materials are low cost, environmental friendly, high efficiency and stability TiO2 has been a strong candidate ... atomic scale, has a great potential for design and synthesis of multifunctional materials with desired and unique properties It can also reduce the cost of materials manufacture The objective of the

Ngày tải lên: 14/10/2020, 18:07

... 12.6), and water was Trang 26The properties of fly ash cement systems studied were chemical and mechanical properties Its chemical properties included the Ca(OH)2 (hereafter, CH) content and the ... high-early-strength Portland cement 3.2 Physical properties of high-early-strength Portland cement 3.4 Physical properties of fly ash 3.7 Physical properties of Master Air 202 3.9 Properties of fresh ... about the effects of fly ash, the mechanisms and effects of internal curing, and the alkali activation on the chemical reaction and the term mechanical properties of the fly ash cement systems Trang

Ngày tải lên: 28/01/2021, 19:04

... for lightweight and high-performance structures in aerospace industry and as coating materials in the maritime and chemical industries [4] The astonishing properties of CNTs in mechanical (axial ... al.[21] considered the mechanical and electrical properties of MWCNT/epoxy composites and found that the Young's modulus is doubled, and the yield strength is quadrupled at 1 and 4 wt % loading of ... tensile and compressive modulus for different wt % were also compared with neat samples 5 Results and discussion 5.1 Tensile properties Most of the important mechanical properties of materials,

Ngày tải lên: 17/03/2021, 20:13

... Yue, J Ren, and X Yuan (2018) Optical Properties of Graphene/MoS 2 Heterostructure: First Principles Calculations Nanomaterials, 8, 962 7 J.-W Jiang and H S Park (2014) Mechanical properties ... enough to modify the intrinsic properties of the constituent monolayers, thus the electronic properties are well preserved Moreover, the optical and mechanical properties of the graphene/MoS ... potentials have prompted scientists to continue to study the outstanding electronic and transport properties of these materials and to explore their application potential for designing high-performance

Ngày tải lên: 28/06/2021, 09:07

... bands at about 2357 and 2311 cm−1, and was observed almost in all stages of the decompositions The spectra, most of the bands of which were commonly observed in both polymers, indicated a band ... vibrations, the formation and assignment of which were reported in a similar analysis,30 and bands at about 1606 and 1510 cm−1 seemingly due to aromatic C=C stretching vibrations The bands at about Trang ... absorption bands, besides those similarly observed in the spectra of the homopolymers, at about 2966 and 2929 cm−1, attributed to the stretching vibrations of CH3 and CH2 groups, and at about 1750 and

Ngày tải lên: 13/01/2022, 00:03

... HDPE, and 2 wt% TEGO-reinforced HDPE specimens TEGO has three main characteristic peaks, which are a D band at 1360 cm−1 related to the amount of defects in the structure, and G and 2D bands at ... size of materials.20 Table 2 summarizes melting and crystallization temperatures of neat and TEGO-reinforced HDPE composites Table 2 Melting and crystallization temperatures of neat and TEGO-reinforced ... processability, nontoxicity, biocompatibility, and good chemical resistance Neat HDPE polymer does not meet industrial demands; the properties of stiffness and rigidity need to be improved Several fillers

Ngày tải lên: 13/01/2022, 00:23

... E F =  m*   * + kbT ln h   me  Eg Since me* and mh* are close and in the ln term, the Fermi level sits about in the center of the band gap ( ) − Eg  k T 2 * * p or n = ni = 2 b  me ... are generated, the Fermi level is approximately in the middle of the band gap • The law of mass action describes the electron and hole populations, since the total number of electron states is fixed ... similar to a chemical reaction, where Eg is the barrier NCNV is the density of the reactants, and n and p are the products N C NV  → e′ + h • Eg − Eg n np =ekT = i N C NV N C NV b • • • Thus,...

Ngày tải lên: 11/08/2014, 14:20

... absorb energy and contribute to properties TF~104K (Troom~102K), EF~100Eclass, vF2~100vclass2 3.225 © E Fitzgerald-1999 Effect of Temperature (T>0): Coupled electronic-thermal properties in conductors ... variable α = ∫ ψ *α op ψ dV v 3.225 © H.L Tuller-2001 19 Time and Spatial Dependence of ψ Assume ψ (x,y,z,t) separable into ψ(x,y,z) and φ(t) Applying separation of variables: − h ∇ 2ψ h ∂φ +V ... Model Traveling wave picture L Standing wave picture Ψ ( x) = Ψ ( x + L) L e ikx = e ik ( x + L ) e ikx = 2πn k= L Just having a boundary condition means that k and E are quasi-continuous, i.e...

Ngày tải lên: 11/08/2014, 14:20

... Means to Create Internal Potentials: Heterojunctions • Different semiconductor materials have different band gaps and electron affinity/work functions Internal fields from doping p-n must be superimposed ... Joining p and n p n Ec EF Ev Carriers flow under driving force of diffusion until EF is flat - - + + + + Holes diffuse Electrons diffuse 3.225 © E Fitzgerald-1999 13 Space Charge, Electric Field and ... increases depletion region, and no current flows ideally Forward Bias Reverse Bias np np eVbi-e|Va| nn nn eVbi-e|Va| pp Solve minority carrier diffusion equations on each side and determine J at depletion...

Ngày tải lên: 11/08/2014, 14:20

... promoted from the valence band to the conduction band E Ec near band gap E=hν k Creates a ‘hole’ in the valence band Ev near band gap 3.225 © E Fitzgerald-1999 Holes and Electrons • • Instead ... 1,000,000 Remember that: 3.225 µ= eτ m* and 1 ∂2E = m * h ∂k 2 Metals and Insulators • EF in mid-band area: free e-, metallic • EF near band edge – EF in or near kT of band edge: semimetal – EF in gap: ... ionic, MP and Eg increase while ao tends to decrease 3.225 © H.L Tuller-2001 Trends in III-V and II-VI Compounds Larger atoms, weaker bonds, smaller U, smaller Eg, higher µ, more costly! Band Gap...

Ngày tải lên: 11/08/2014, 14:20