The Effect of Plastic Deformation on Nitrogen Diffusion in α-Fe

2011 ◽  
Vol 309-310 ◽  
pp. 155-160
Author(s):  
Lesya Demchenko ◽  
Sergey I. Sidorenko
Keyword(s):  
Electron Microscopy ◽  
Plastic Deformation ◽  
Surface Diffusion ◽  
Nitrogen Diffusion ◽  
X Ray ◽  
Microhardness Test ◽  
Preliminary Plastic Deformation ◽  
Diffusion Layers ◽  
Ammonia Medium

The surface diffusion layers formed in preliminary deformed (350 %) -Fe after nitriding at 853 K in ammonia medium were studied by means of metallography, electron microscopy, microhardness test and X-ray powder diffractometry. The preliminary plastic deformation (PPD) effects non-monotonously on the structure, microhardness and thickness of nitride - and -phases layers formed in -Fe. The narrow intervals of deformations of 3-8 % and 20-30 % were found in which the accelerated formation of nitride - and -phases occurs.

Tribological Properties of Nanostructured Diffusion Layers of Metal Coatings

2016 ◽  
Vol 721 ◽  
pp. 446-450 ◽  
Author(s):  
Margarita A. Skotnikova ◽  
Galina V. Tsvetkova ◽  
Nikolay A. Krylov
Keyword(s):  
Plastic Deformation ◽  
Spectral Analysis ◽  
Tribological Properties ◽  
Nanostructured Surface ◽  
High Angle ◽  
X Ray Diffraction ◽  
Electronic Microscopy ◽  
Metal Coatings ◽  
X Ray ◽  
Diffusion Layers

Copper nickel (Cu-Ni) coatings on products from instrumental steel H12M were drawn and they were subjected to subsequent intensive plastic deformation under stresses 3.0; 3.5; 4.0 and 4.5 GPa. The nanostructured surface, formation grains size of 13...173 nm with high-angle (at 3.0; 4.0; 4.5 GPa) and low-angle (dislocation) borders of grains (at 3.5 GPa), influencing redistribution of alloying elements and tribological properties was shown by means of methods of light and electronic microscopy, X-ray diffraction and micro-ray spectral analysis, and also tribological tests.

scholarly journals Magnetic Binary Supersaturated Solid Solutions Processed by Severe Plastic Deformation

Nanomaterials ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 6 ◽  
Author(s):  
Martin Stückler ◽  
Heinz Krenn ◽  
Reinhard Pippan ◽  
Lukas Weissitsch ◽  
Stefan Wurster ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Plastic Deformation ◽  
High Pressure Torsion ◽  
Magnetic Measurements ◽  
Ferromagnetic Behavior ◽  
Dual Phase ◽  
X Ray Diffraction ◽  
Magnetic Phases ◽  
X Ray ◽  
Supersaturated Solid Solutions

Samples consisting of one ferromagnetic and one diamagnetic component which are immiscible at the thermodynamic equilibrium (Co-Cu, Fe-Cu, Fe-Ag) are processed by high-pressure torsion at various compositions. The received microstructures are investigated by electron microscopy and synchrotron X-ray diffraction, showing a microstructural saturation. Results gained from microstructural investigations are correlated to magnetometry data. The Co-Cu samples show mainly ferromagnetic behavior and a decrease in coercivity with increasing Co-content. The saturation microstructure of Fe-Cu samples is found to be dual phase. Results of magnetic measurements also revealed the occurrence of two different magnetic phases in this system. For Fe-Ag, the microstructural and magnetic results indicate that no intermixing between the elemental phases takes place.

Surface Properties of 316L Austenitic Steel Improved by Simultaneous Diffusion of Titanium and Aluminium

2010 ◽  
Vol 297-301 ◽  
pp. 1-7 ◽  
Author(s):  
Iulia Mirela Britchi ◽  
Niculae Ene ◽  
Mircea Olteanu ◽  
Eugeniu Vasile ◽  
Petru Nita ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Austenitic Steel ◽  
Vickers Microhardness ◽  
Thermochemical Treatment ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffusion Coatings ◽  
Diffusion Layers ◽  
Scanning Electron ◽  
Titanium Aluminium

Samples of 316L austenitic steel were submitted to a thermochemical treatment which implies surface diffusion of Al and Ti. The technique of pack cementation with NH4Cl as activator was employed. The powder mixture was made of aluminium, titanium, aluminium oxide and ammonium chloride. The same ratio of Al : Ti = 1 : 5 was used in all experiments. The variables were temperature and time. As a function of these parameters, diffusion layers of different thicknesses were obtained. The samples were analyzed by optical microscopy, scanning electron microscopy (SEM) and energy dispersive X-ray microanalysis (EDX), X-ray diffraction and Vickers microhardness trials. All layers were formed by diffusion with reaction and present two zones with different structures and compositions and therefore different properties. The Ti3NiAl2N compound was identified by X-ray diffraction. The presence of this compound in the diffusion coatings increases the superficial hardness of the samples.

Hysteresis Magnetic Properties of Nd-Ho-Fe-Co-B Alloys after Intense Plastic Deformation

2010 ◽  
Vol 667-669 ◽  
pp. 1065-1070 ◽  
Author(s):  
Irina S. Tereshina ◽  
Evgeniya A. Tereshina ◽  
Gennady S. Burkhanov ◽  
Sergey V. Dobatkin
Keyword(s):  
Electron Microscopy ◽  
Plastic Deformation ◽  
Magnetic Properties ◽  
Severe Plastic Deformation ◽  
Structural State ◽  
Structural Investigation ◽  
Magnetic Hysteresis ◽  
Induction Melting ◽  
X Ray ◽  
Hysteresis Properties

In the present work a study of the influence of structural state on magnetic hysteresis properties of (Nd,Ho)2(Fe0.8Co0.2)14B compound was carried out. Starting alloy was prepared by induction melting in an Ar atmosphere. Nd-Ho-Fe-Co-B alloys with a nanograin structure were obtained by severe plastic deformation (SPD). Electron microscopy and X-ray analysis were used for the structural investigation. The magnetization measurements were performed using a SQUID magnetometer. It is shown that the relatively high values of coercive force are observed in case of achieved nanograin structure in (Nd,Ho)2(Fe0.8Co0.2)14B. The effect of structural state on hysteresis properties of Y2(Fe0.8Co0.2)14B is also investigated.

scholarly journals Processing of Nanostructured Bulk Fe-Cr Alloys by Severe Plastic Deformation

2021 ◽  
Vol 1016 ◽  
pp. 1603-1610
Author(s):  
Lukas Weissitsch ◽  
Martin Stückler ◽  
Stefan Wurster ◽  
Richard Pippan ◽  
Andrea Bachmaier
Keyword(s):  
Electron Microscopy ◽  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
High Pressure Torsion ◽  
Chemical Compositions ◽  
X Ray Diffraction ◽  
Thermodynamical Equilibrium ◽  
X Ray ◽  
Σ Phase ◽  
Arc Melting

The processing of binary alloys consisting of ferromagnetic Fe and antiferromagnetic Cr by severe plastic deformation (SPD) with different chemical compositions has been investigated. Although the phase diagram exhibits a large gap in the thermodynamical equilibrium at lower temperatures, it is shown that techniques based on SPD help to overcome common processing limits. Different processing routes including initial ball milling (BM) and arc melting (AM) and a concatenation with annealing treatments prior to high-pressure torsion (HPT) deformation are compared in this work. Investigation of the deformed microstructures by electron microscopy and synchrotron X-ray diffraction reveal homogeneous, nanocrystalline microstructures for HPT deformed AM alloys. HPT deformation of powder blends and BM powders leads to an exorbitant increase in hardness or an unusual fast formation of a σ-phase and therefore impede successful processing.

Quaternary structure of Limulus polyphemus hemocyanin

1978 ◽  
Vol 36 (2) ◽  
pp. 176-177
Author(s):  
T. Wichertjes ◽  
E.J. Kwak ◽  
E.F.J. Van Bruggen
Keyword(s):  
Electron Microscopy ◽  
Functional Properties ◽  
Horseshoe Crab ◽  
Temperature Jump ◽  
Quaternary Structure ◽  
Crystallographic Analysis ◽  
Limulus Polyphemus ◽  
Oxygen Binding ◽  
X Ray ◽  
Intact Molecule

Hemocyanin of the horseshoe crab (Limulus polyphemus) has been studied in nany ways. Recently the structure, dissociation and reassembly was studied using electron microscopy of negatively stained specimens as the method of investigation. Crystallization of the protein proved to be possible and X-ray crystallographic analysis was started. Also fluorescence properties of the hemocyanin after dialysis against Tris-glycine buffer + 0.01 M EDTA pH 8.9 (so called “stripped” hemocyanin) and its fractions II and V were studied, as well as functional properties of the fractions by NMR. Finally the temperature-jump method was used for assaying the oxygen binding of the dissociating molecule and of preparations of isolated subunits. Nevertheless very little is known about the structure of the intact molecule. Schutter et al. suggested that the molecule possibly consists of two halves, combined in a staggered way, the halves themselves consisting of four subunits arranged in a square.

Phase Transformations in Ti-7w/oMo-3w/oMe Alloy

1974 ◽  
Vol 32 ◽  
pp. 514-515
Author(s):  
S. Fujishiro
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Transmission Electron Microscopy ◽  
Tensile Strength ◽  
Mechanical Processing ◽  
Ray Method ◽  
X Ray ◽  
Transmission Electron ◽  
Water Quench ◽  
Alpha Beta

The mechanical properties of three titanium alloys (Ti-7Mo-3Al, Ti-7Mo- 3Cu and Ti-7Mo-3Ta) were evaluated as function of: 1) Solutionizing in the beta field and aging, 2) Thermal Mechanical Processing in the beta field and aging, 3) Solutionizing in the alpha + beta field and aging. The samples were isothermally aged in the temperature range 300° to 700*C for 4 to 24 hours, followed by a water quench. Transmission electron microscopy and X-ray method were used to identify the phase formed. All three alloys solutionized at 1050°C (beta field) transformed to martensitic alpha (alpha prime) upon being water quenched. Despite this heavily strained alpha prime, which is characterized by microtwins the tensile strength of the as-quenched alloys is relatively low and the elongation is as high as 30%.

Sem Studies of Co-Cr-Mo Surgical Implant Alloy Corrosion Behavior

1982 ◽  
Vol 40 ◽  
pp. 520-521
Author(s):  
Ann Chidester Van Orden ◽  
John L. Chidester ◽  
Anna C. Fraker ◽  
Pei Sung
Keyword(s):  
Electron Microscopy ◽  
Corrosion Behavior ◽  
Anodic Polarization ◽  
Saline Solution ◽  
Saturated Calomel Electrode ◽  
Physiological Saline ◽  
X Ray ◽  
Physiological Saline Solution ◽  
Scanning Electron

The influence of small variations in the composition on the corrosion behavior of Co-Cr-Mo alloys has been studied using scanning electron microscopy (SEM), energy dispersive x-ray analysis (EDX), and electrochemical measurements. SEM and EDX data were correlated with data from in vitro corrosion measurements involving repassivation and also potentiostatic anodic polarization measurements. Specimens studied included the four alloys shown in Table 1. Corrosion tests were conducted in Hanks' physiological saline solution which has a pH of 7.4 and was held at a temperature of 37°C. Specimens were mechanically polished to a surface finish with 0.05 µm A1203, then exposed to the solution and anodically polarized at a rate of 0.006 v/min. All voltages were measured vs. the saturated calomel electrode (s.c.e.).. Specimens had breakdown potentials near 0.47V vs. s.c.e.

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