Stability of disperse particles in a metallic matrix with slipping friction

2011 ◽  
Vol 31 (2) ◽  
pp. 133-135
Author(s):  
V. V. Zyablitsev ◽  
O. V. Zyablitsev
Keyword(s):  
Metallic Matrix ◽  
Disperse Particles ◽  
Slipping Friction

scholarly journals The Use of Ion Milling for Surface Preparation for EBSD Analysis

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3970
Author(s):  
Wojciech J. Nowak
Keyword(s):  
Plasma Etching ◽  
Ion Beam ◽  
Metallic Matrix ◽  
Surface Preparation ◽  
Optical Emission ◽  
Alternative Methods ◽  
Ebsd Analysis ◽  
Crystallographic Structure ◽  
Ion Milling ◽  
Electron Backscattered Diffraction

An electron backscattered diffraction (EBSD) method provides information about the crystallographic structure of materials. However, a surface subjected to analysis needs to be well-prepared. This usually requires following a time-consuming procedure of mechanical polishing. The alternative methods of surface preparation for EBSD are performed via electropolishing or focus ion beam (FIB). In the present study, plasma etching using a glow discharge optical emission spectrometer (GD-OES) was applied for surface preparation for EBSD analysis. The obtained results revealed that plasma etching through GD-OES can be successfully used for surface preparation for EBSD analysis. However, it was also found that the plasma etching is sensitive for the alloy microstructure, i.e., the presence of intermetallic phases and precipitates such as carbides possess a different sputtering rate, resulting in non-uniform plasma etching. Preparation of the cross-section of oxidized CM247 revealed a similar problem with non-uniformity of plasma etching. The carbides and oxide scale possess a lower sputtering rate than the metallic matrix, which caused formation of relief. Based on obtained results, possible resolutions to suppress the effect of different sputtering rates are proposed.

Morphological characterisation of 2D packing with bi-disperse particles

2021 ◽  
Vol 13 (1) ◽  
pp. 89-97
Author(s):  
Mingrui Dong ◽  
Joerg Reimann ◽  
Ratna Kumar Annabattula ◽  
Yixiang Gan
Keyword(s):  
Morphological Characterisation ◽  
Disperse Particles

scholarly journals Dispersion of metallic/ceramic matrix nanocomposite material through porous surfaces in magnetized hybrid nanofluids flow with shape and size effects

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Zubair Akbar Qureshi ◽  
S. Bilal ◽  
M. Y. Malik ◽  
Qadeer Raza ◽  
El-Sayed M. Sherif ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Viscous Fluid ◽  
Metallic Matrix ◽  
Ceramic Matrix ◽  
Physical Parameters ◽  
Viscous Fluid Flow ◽  
Hybrid Nanofluids ◽  
Matrix Nanocomposites ◽  
Matrix Nanocomposite

AbstractMatrix nanocomposites are high performance materials possessing unusual features along with unique design possibilities. Due to extraordinary thermophysical characteristic contained by these matrix nanocomposites materials they are useful in several areas ranging from packaging to biomedical applications. Being an environment friendly, utilization of nanocomposites offer new technological opportunities for several sectors of aerospace, automotive, electronics and biotechnology. In this regards, current pagination is devoted to analyze thermal features of viscous fluid flow between orthogonally rotating disks with inclusion of metallic matrix nanocomposite (MMNC) and ceramic matrix nanocomposites (CMNC) materials. Morphological aspects of these nanomaterials on flow and heat transfer characteristics has been investigated on hybrid viscous fluid flow. Mathematical structuring of problem along with empirical relations for nanocomposites materials are formulated in the form of partial differential equations and later on converted into ordinary differential expressions by using suitable variables. Solution of constructed coupled differential system is found by collaboration of Runge–Kutta and shooting methods. Variation in skin friction coefficient at lower and upper walls of disks along with measurement about heat transfer rate are calculated against governing physical parameters. Impact of flow concerning variables on axial, radial components of velocity and temperature distribution are also evaluated. Contour plots are also drawn to explore heat and thermal profiles. Comparison and critical analysis of MMNc and CMNc have been presented at lower and upper porous disks. Our computed analysis indicates that hybrid nanofluids show significant influence as compared to simple nanofluids with the permutation of the different shape factors.

Charging of disperse particles in two-phase media with unipolar charge

1981 ◽  
Vol 15 (6) ◽  
pp. 880-886
Author(s):  
N. L. Vasil'eva ◽  
L. T. Chernyi
Keyword(s):  
Two Phase ◽  
Disperse Particles

Orientation relationships of carlsbergite in schreibersite and kamacite in the north Chile iron meteorite

2006 ◽  
Vol 70 (4) ◽  
pp. 373-382 ◽  
Author(s):  
G. Nolze ◽  
G. Wagner ◽  
R. Saliwan Neumann ◽  
R. Skála ◽  
V. Geist
Keyword(s):  
Electron Backscatter Diffraction ◽  
Metallic Matrix ◽  
Iron Meteorite ◽  
Orientation Relationships ◽  
Orientation Relation ◽  
Crystalline Materials ◽  
The North ◽  
Transmission Electron ◽  
Backscatter Diffraction ◽  
General Connection

AbstractThe crystallographic orientation of carlsbergite (CrN) in the north Chile meteorite (hexahedrite) was investigated using electron backscatter diffraction and transmission electron microscopy. These studies examined the CrN crystals in the rhabdites (idiomorphic schreibersite) and in kamacite. It was found that the CrN crystals embedded in rhabdite show a number of different orientation relationships with the host crystals. These orientations can be explained based on the lattice dimensions of both coexisting crystalline materials. It was also found that both carlsbergite and kamacite are characterized by a high dislocation density (≥ l09 cm-2) while rhabdite is free of dislocations. It is supposed that in spite of the deformed metallic matrix, a general connection between the orientation relation of all the phases involved exists.

Dissolution Behavior of Cast WC Particles in NiCrBSi-WC Coatings by Laser Induction Hybrid Cladding

2013 ◽  
Vol 668 ◽  
pp. 283-287
Author(s):  
Sheng Feng Zhou ◽  
Xiao Qin Dai
Keyword(s):  
High Speed ◽  
Laser Scanning ◽  
Metallic Matrix ◽  
High Hardness ◽  
Scanning Speed ◽  
Eutectic Structure ◽  
Dissolution Behavior ◽  
Positive Role ◽  
Laser Scanning Speed ◽  
Laser Induction

In order to characterize the dissolution of cast WC particles in Ni-based WC coatings by laser induction hybrid rapid cladding, NiCrBSi+50 wt.% WC coatings are produced on A3 steel by low and high speed laser induction hybrid cladding (LIHC). When laser scanning speed is only 600 mm/min, the crack-free coating has pores and its dilution is as high as 45%. At the bottom of coating, the cast WC particles are dissolved completely and the herringbone M6C eutectics are precipitated. In the center of coating, the cast WC particles are also dissolved completely and the acicular, blocky and dendritic carbides with relatively low hardness are precipitated. At two sides of coating, some cast WC particles are dissolved partially and interact with Ni-based alloy to form an alloyed reaction layer, while others preserve the primary eutectic structure and high hardness. When laser scanning speed and powder feeding rate are increased to 1500 mm/min and 85.6 g/min, the coating has cracks but no pores. Its dilution can be markedly decreased to 7.8%. Moreover, a majority of WC particles are still composed of primary eutectic structure and keep their high hardness, which can play a positive role in strengthening Ni-based metallic matrix.

Novel Inorganic Hydrogels Based on The Polymerization of Cyanometalate Transition Metal Complexes With [PdCl4]2-: A New Approach To Ceramic And Alloy Precursors

1994 ◽  
Vol 346 ◽  
Author(s):  
Andrew B. Bocarsly ◽  
Gireesh Kumar ◽  
Marija Heibel
Keyword(s):  
Transition Metal ◽  
Metal Ion ◽  
Sol Gel ◽  
Metallic Matrix ◽  
Linear Polymers ◽  
New Approach ◽  
Square Planar ◽  
Delafossite Structure ◽  
Cyanide Ligand ◽  
Sol Gel Transition

ABSTRACTThe reaction of a wide variety of cyanometalate complexes of the general form [M(CN)x]n- (where M= a transition metal ion) with square planar [PdCl4]2- in aqueous solution leads to the formation of linear polymers. Polymerization occurs via substitution of chloride ligands on the Pd(II) centers, by the nitrogen end of the cyanide ligand to generate extended bridging cyanide structures. Upon generation at room temperature polymer solutions of this type under go a sol-gel transition to generate robust hydrogels having water content in excess of 95%. In the case of the cyanocobaltate/tetrachloropalladate gel, pyrolysis at 900°C produces ferromagnetic Pd/Co metallic alloys having novel morphological character. Materials formed with a hydrogel having a 2:1 Pd to Co stoichiometry are found to be “sponge-like”. When placed in water, the metallic matrix swells becoming pliable and holding up to seven equivalents of water per metal site. The conductivity and magnetic properties of this material are maintained in the swollen state. Sintering of the Pd/Co hydrogel in air generates the layered oxide, PbCoO2 having a delafossite structure.

Microstructure and Properties of TiC-CrNiMo SHS Spray Powder and Thermally Sprayed Coating

2000 ◽  
Author(s):  
M. Väisänen ◽  
P. Vuoristo ◽  
T. Mäntylä ◽  
V. Maunu ◽  
P. Lintunen ◽  
...  
Keyword(s):  
Particle Size ◽  
Corrosion Behaviour ◽  
Metallic Matrix ◽  
Electrochemical Corrosion ◽  
Wear Test ◽  
Spherical Shape ◽  
Open Circuit ◽  
Hvof Spraying ◽  
Particle Size Range ◽  
Abrasion Wear

Abstract Titanium carbide cermet spray powder was produced by the SHS process (Self-propagating High-temperature Synthesis) using elemental Ti, C, Mo and prealloyed CrNiMo powders as starting materials. The powder was characterised (particle size distribution, phase structure, morphology) and the internal structure of each cermet particle was found out to be dense consisting of fine distribution of carbides embedded in a metallic matrix. The particle size range suitable for thermal spraying was obtained by sieving and air classifying. The coatings were prepared by HVOF spraying (DJH2600 and DJH2700). The dry abrasion wear resistance was evaluated by the rubber wheel abrasion wear test and electrochemical corrosion behaviour by open circuit potential measurements. According to the XRD analysis the amount of retained carbides in the coatings is high and the carbide phase has a spherical shape also in the coatings. The microstructure of coatings obtained is dense and the coatings possess good properties in wear and corrosion tests. WC-Co-Cr and Cr3C2-NiCr powders were used for comparison.

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