scholarly journals INVESTIGATIONS OF DENSITY AND POROSITY OF COATINGS MADE OF CERAMIC-POLYMERIC OR COMPOSITES WITH QUASI-CRYSTALS OBTAINED WITH GAS-DETONATION METHOD AND METHOD OF GAS-DYNAMIC SPUTTERING

2020 ◽  
Vol 2020 (7) ◽  
pp. 4-11
Author(s):  
Ol'ga Sil'chenko ◽  
Marina Siluyanova ◽  
Petr Hopin
Keyword(s):  
Grain Structure ◽  
Titanium Carbonitride ◽  
Coarse Grain ◽  
Friction Unit ◽  
Gradual Change ◽  
Gas Detonation ◽  
Fine Grain ◽  
Gas Dynamic ◽  
Quasi Crystals ◽  
Maximum Parameters

The work purpose consists in the development of the procedure for density and strength definition through the method of hydro-static weighing in relation to titanium carbonitride-based coatings. The development object – quasi-crystals based titanium carbonitride clad with nickel. Novelty and urgency of this work are based on the creation of polymeric antifriction materials intended for operation in the mode of hydro-dynamic friction. Frictionless and slider bearings with anti-friction coatings are the most efficient structures allowing the considerable increase of capacity and reliability of friction unit operation in machinery. There are presented microstructure photos of coatings obtained with the method of gas-dynamic sputtering. As a result of the technology developed it is defined that at the base a coating has the VN20 coarse-grain which has maximum parameters of static strength (bending, tearing and adhesion strength) at the expense of its structure and coarse grain. As we move forward from the layer adjoining the base to the operation one of the coating we observe the decrease of structure grain (from 100 to 15 mkm) and a gradual change of the composition, micro-hardness increase. As a result a carrying layer of KNTP35 coating has maximum parameters of long strength at the expense of a fine-grain structure and composition. It is characterized with increased resistance to thermal blow, tacking, spalling and higher impact elasticity and wear-resistance. In the paper there is offered a method of hydro-static weighing for the determination of density and porosity regarding coatings. According to the optimum technological mode are made samples and their porosity and density are investigated.

Microstructure Evolution of Copper by Three Roll Planetary Milling

2018 ◽  
Vol 279 ◽  
pp. 44-48 ◽  
Author(s):  
Yu Wei Zhou ◽  
Ze Ning Mao ◽  
Ying Liu ◽  
Jing Tao Wang
Keyword(s):  
Dynamic Recrystallization ◽  
Pure Copper ◽  
Milling Process ◽  
Planetary Mill ◽  
Grain Structure ◽  
Coarse Grain ◽  
Engineering Strain ◽  
Fine Grain ◽  
Equiaxed Grains ◽  
Equiaxed Grain

The microstructure of commercial pure copper TP2 tube by three roll planetary mill processing was investigated. Due to work hardening and subsequent softing by dynamic recrystallization during milling process,the coarse grain structure of the copper transformed to fine grain structure. The grain refinement is achieved along the axial moving in general; in the reducing zone, the sample has a gradient structure along the radial direction; uniform equiaxed grain with size of ~2 μm could be obtained at the outlet. The initiation of dynamic recrystallization occurred in the three roll planetary mill the reduction engineering strain reach ~30%, where some equiaxed grains replaced the elongated grains because of recrystallization.

scholarly journals STRENGTH PROPERTIES INVESTIGATION OF COMPOSITE COATINGS WITH QUASI-CRYSTALS OBTAINED THROUGH METHODS OF GAS DYNAMIC SPUTTERING

2020 ◽  
Vol 2020 (12) ◽  
pp. 11-18
Author(s):  
Ol'ga Sil'chenko ◽  
Marina Siluyanova ◽  
Petr Hopin
Keyword(s):  
Impact Load ◽  
Composite Coatings ◽  
Strength Properties ◽  
Titanium Carbonitride ◽  
New Materials ◽  
Gas Dynamic ◽  
Strength Based ◽  
Quasi Crystals ◽  
The Impact ◽  
High Separation

The work purpose is to investigate strength properties of composite coatings with quasi-crystals obtained through the method of gas dynamic sputtering. The object of development: quasi-crystals based on titanium carbonitride clad with nickel. In the course of the work there is offered a method for investigations of coating strength based on a pin and adhesive method with composites based on titanium carbonitride. The novelty of this investigation consists in obtaining new materials and investigations of their physical-mechanical properties. Composite coating on the basis of titanium carbonitride has shown high separation properties. The destruction took place in an intermediate layer between VN20 and KNTP35. During 10 mm bending there is a fine even mesh. At the impact load made there were not observed chips and separations that allow using coating data in heavy-loaded parts.

Isotropic and Anisotropic Nanocrystalline NdFeB-Based Magnets Prepared by Spark Plasma Sintering and Hot Deformation

2012 ◽  
Vol 510-511 ◽  
pp. 307-314 ◽  
Author(s):  
Zhong Wu Liu ◽  
Y.L. Huang ◽  
H.Y. Huang ◽  
X.C. Zhong ◽  
Hong Ya Yu ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Grain Growth ◽  
Spark Plasma Sintering ◽  
Hot Deformation ◽  
Grain Structure ◽  
Coarse Grain ◽  
Fine Grain ◽  
Plasma Sintering ◽  
Melt Spun ◽  
Spark Plasma

Isotropic and anisotropic NdFeB permanent magnets were prepared by Spark Plasma Sintering (SPS) and SPS followed hot deformation (HD), respectively, using melt spun NdFeB ribbons with various compositions as starting materials. It is found that, based on RE-rich composition, SPSed magnets sintered at low temperatures (<700 C) almost maintained the uniform fine grain structure inherited from rapid quenching. At higher temperatures, a distinct two-zone (coarse grain and fine grain zones) structure was formed in the SPSed magnets. The SPS temperature and pressure have important effects on the grain structure, which led to the variations in the magnetic properties. By employing low SPS temperature and high pressure, high-density magnets with negligible coarse grain zone and an excellent combination of magnetic properties can be obtained. For single phase NdFeB alloy, because of the deficiency of Nd-rich phases, it is relatively difficult to consolidate micro-sized melt spun powders into high density bulk magnet, but generally a larger particle size is beneficial to achieve better magnetic properties. Anisotropic magnets with a maximum energy product of ~38 MGOe were produced by the SPS+HD process. HD did not lead to obvious grain growth and the two-zone structure still existed in the hot deformed magnets. The results indicated that nanocrystalline NdFeB magnets without significant grain growth and with excellent properties could be obtained by SPS and HD processes.

Microstructure Development in a High Current Density NbTi Superconducting Composite

1985 ◽  
Vol 43 ◽  
pp. 186-189
Author(s):  
P. J. Lee ◽  
D. C. Larbalestier
Keyword(s):  
Current Density ◽  
High Current Density ◽  
Cold Drawing ◽  
Heat Treatments ◽  
Grain Structure ◽  
Fine Grain ◽  
Boundary Film ◽  
Quantitative Basis ◽  
Cold Worked ◽  
Very High

Several features of the metallurgy of superconducting composites of Nb-Ti in a Cu matrix are of interest. The cold drawing strains are generally of order 8-10, producing a very fine grain structure of diameter 30-50 nm. Heat treatments of as little as 3 hours at 300 C (∼ 0.27 TM) produce a thin (1-3 nm) Ti-rich grain boundary film, the precipitate later growing out at triple points to 50-100 nm dia. Further plastic deformation of these larger a-Ti precipitates by strains of 3-4 produces an elongated ribbon morphology (of order 3 x 50 nm in transverse section) and it is the thickness and separation of these precipitates which are believed to control the superconducting properties. The present paper describes initial attempts to put our understanding of the metallurgy of these heavily cold-worked composites on a quantitative basis. The composite studied was fabricated in our own laboratory, using six intermediate heat treatments. This process enabled very high critical current density (Jc) values to be obtained. Samples were cut from the composite at many processing stages and a report of the structure of a number of these samples is made here.

CONTINUOUS-CAST 45-12 DUCTILE IRON

Alloy Digest ◽  
1989 ◽  
Vol 38 (4) ◽  
Keyword(s):  
Continuous Casting ◽  
Ductile Iron ◽  
Heat Treating ◽  
Grain Structure ◽  
Continuous Cast ◽  
Good Surface ◽  
Fine Grain ◽  
High Speeds ◽  
Good Surface Finish ◽  
Iron Grade

Abstract Ductile Iron grade 45-12 produced by continuous casting has consistent density and fine grain structure. It is the softest of the regular grades of ductile iron and it machines at high speeds with good surface finish. This datasheet provides information on composition, physical properties, microstructure, hardness, elasticity, and tensile properties. It also includes information on heat treating, machining, and joining. Filing Code: CI-58. Producer or source: Federal Bronze Products Inc..

KETOS

Alloy Digest ◽  
1960 ◽  
Vol 9 (8) ◽  
Keyword(s):  
Physical Properties ◽  
Tensile Properties ◽  
Tool Steel ◽  
Heat Treating ◽  
Grain Structure ◽  
Steel Company ◽  
Fine Grain ◽  
Crucible Steel

Abstract KETOS is an oil-hardening non-deforming tool steel having deep hardening qualities with a fine grain structure. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as deformation. It also includes information on forming, heat treating, and machining. Filing Code: TS-96. Producer or source: Crucible Steel Company of America.

Ionic Conductivities of Doped CeO2 Thin Films as Related to Their Microstructure

1995 ◽  
Vol 411 ◽  
Author(s):  
Chunyan Tian ◽  
Siu-Wai Chan
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Ionic Conductivities ◽  
Dielectric Constants ◽  
Grain Structure ◽  
X Ray Diffraction ◽  
Fine Grain ◽  
Brick Layer Model ◽  
Columnar Grain ◽  
Beam Deposition

ABSTRACTThin films of 4% Y2O3 doped CeO2/Pd film/(001)LaA103 with a very low pinhole density were successfully prepared using electron-beam deposition technique. The microstructure of the films was characterized by x-ray diffraction and the electrical properties were studied as a function of temperature with AC impedance spectroscopy. A brick layer model was adopted to correlate the electrical properties to the microstructure of the films, which can be simplified as either a series or a parallel equivalent circuit associated with either a fine grain or a columnar grain structure, respectively. The conductivities of the films fell between the conductivities derived from the two circuit models, suggesting that the films are of a mixed fine grain and columnar grain structure. The measured dielectric constants of the films were found smaller than that of the bulk.

Magnetic properties of MnZn ferrite with ultra-fine grain structure

2003 ◽  
Vol 254-255 ◽  
pp. 538-540 ◽  
Author(s):  
J Moulin ◽  
Y Champion ◽  
J.M Grenèche ◽  
F Mazaleyrat
Keyword(s):  
Magnetic Properties ◽  
Grain Structure ◽  
Mnzn Ferrite ◽  
Fine Grain

The Possibility of Manufacturing Long-Length Metal Products with Ultra-Fine Grain Structure by Combination of Strain Effects

2016 ◽  
Vol 685 ◽  
pp. 487-491 ◽  
Author(s):  
Mikhail Chukin ◽  
Marina Polyakova ◽  
Alexandr Gulin ◽  
Olga Nikitenko
Keyword(s):  
Steel Wire ◽  
Continuous Method ◽  
Grain Structure ◽  
Strain Effect ◽  
Strain Effects ◽  
Fine Grain ◽  
Wide Range ◽  
Processing Modes ◽  
Efficiency Estimation ◽  
Metal Products

It is shown that combination of strain effects leads to possessing the ultra-fine grain structure in carbon wire. The continuous method of wire deformation nanostructuring was developed on the basis of simultaneous applying of tension deformation by drawing, bending deformation when going through the system of rolls and torsional deformation on a continuously moving wire. One of the main advantages of the developed method is that various hardware devices and tools already applied for steel wire production can be used to implement this method thus simplifying its introduction to the current industrial equipment. The efficiency estimation of the developed continuous method of deformation nanostructuring was carried out using carbon wire with different carbon content. It is shown that the mechanical properties of the wire after combination of different kinds of strain can vary over a wide range. This method makes it possible to choose such modes of strain effect, which can provide the necessary combination of strength and ductile properties of carbon wire depending on its further processing modes and application.

Microstructural Changes of Welded Zn-AI Alloy

1994 ◽  
Vol 367 ◽  
Author(s):  
Yao Hua Zhu
Keyword(s):  
Phase Transformation ◽  
Early Stage ◽  
Dendritic Structure ◽  
Metastable Phases ◽  
Grain Structure ◽  
Al Alloy ◽  
Cast State ◽  
Microstructural Changes ◽  
Fine Grain ◽  
Ageing Processes

AbstractExtruded eutectoid Zn-Al alloy was welded by a melt of the same eutectoid alloy. Two different microstructures were observed in the joint part and the bulk of the welded alloy. Typical dendritic structure of as cast Zn-Al alloy was observed in the joint part of the welded alloy. The bulk ofthe welded Zn-Al alloy appeared as fine grain structure. Two different metastable phases η'T decomposed from η's of chilled as cast state and η'E of extruded state were found to be unstable during early stage of ageing. A four phase transformation occurred after the decompositions of these two metastable phases of η'T. Microstructures of both joint part and bulk of the welded alloy were investigated parallely during ageing processes.

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