Model of growth kinetics of nitrided layer in the binary Fe–N system

2004 ◽  
Vol 95 (9) ◽  
pp. 823-828 ◽  
Author(s):  
Jerzy Ratajski
Keyword(s):  
Growth Kinetics ◽  
Nitrided Layer ◽  
Kinetics Of

Characterization and growth kinetics of plasma nitrided layer fabricated on Incoloy 901 superalloy

2020 ◽  
Vol 396 ◽  
pp. 125960
Author(s):  
Hongjian Huang ◽  
Xiaowei Wei ◽  
Haiyan He ◽  
Yuhao Wu ◽  
Jianhui Qiu
Keyword(s):  
Growth Kinetics ◽  
Nitrided Layer ◽  
Kinetics Of

Growth Kinetics of Hardened Layers Produced during Nitriding in Ammonia Gas Environments

2006 ◽  
Vol 526 ◽  
pp. 109-114 ◽  
Author(s):  
S. Mridha
Keyword(s):  
Growth Kinetics ◽  
White Layer ◽  
Nitrided Layer ◽  
Case Depth ◽  
Iron Nitride ◽  
Gas Mixture ◽  
Optimum Level ◽  
Low Alloy Steels ◽  
Ammonia Content ◽  
Kinetics Of

In gas nitriding the thickness of the case depth is reported to increase parabolically with processing time and ammonia content in the NH3/H2 gas mixture which consequently increases the thickness of undesirable surface iron-nitride (white layer). In this investigation two commercial grade low alloy steels were nitrided in gas atmospheres containing 10 to 80% ammonia at 4700, 5200 and 5700C for 6 to 96 h. A metallographic technique was used to reveal different zones of the nitrided surface and the thickness of the diffusion zone was recorded using microscope. The growth kinetics of the diffusion layer of these two steels were analyzed and compared with that of 3% chromium (En40B) steel from literature. The results of the investigation conclusively suggest that the growth rate of the nitrided layer for both steels reached to a maximum with the increase of ammonia content in the gas mixture up to an optimum level where the thickness of the white layer is a minimum. However, the growth rates of the nitrided case are different for different steels.

scholarly journals The Effects of Modifying the Activity of Nitriding Media by Diluting Ammonia with Nitrogen

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2432
Author(s):  
Mihai Ovidiu Cojocaru ◽  
Mihai Branzei ◽  
Andrei Mihai Ghinea ◽  
Leontin Nicolae Druga
Keyword(s):  
Growth Kinetics ◽  
Nitrided Layer ◽  
Gaseous Mixture ◽  
Ammonia Nitrogen ◽  
Layer Growth ◽  
Gaseous Ammonia ◽  
Kinetics Parameters ◽  
Nitrogen Dilution ◽  
Nitrogen Mixture ◽  
Kinetics Of

This paper discusses the issue of the effects of modifying the activity of nitriding media by diluting ammonia with nitrogen and the concomitant variation in the degree of ammonia dissociation on the layer’s growth kinetics and their phase composition. To understand and quantify the effects of the variation in the main parameters that influence the layer growth kinetics, the experimental programming method was used and mathematical models of interactions between influence and kinetics parameters were obtained for two metallic materials: Fe-ARMCO and 34CrAlMo5 nitralloy steel. It was concluded that the nitriding operating temperature and the degree of nitrogen dilution of the ammonia have statistically significant influences on the kinetics of the nitrided layer. In the same context, it was analytically proved and experimentally confirmed that the ammonia degree dissociation from the gaseous ammonia-nitrogen mixture, along with the dilution degree of the medium with nitrogen, significantly influences the nitrogen potential of the gaseous mixture used for nitriding and thus the concentration of nitrogen in balance at the medium thermochemically processed metal product interface.

The Ordered Phase Formation in Ti-Al-Ga Alloys

1970 ◽  
Vol 28 ◽  
pp. 440-441
Author(s):  
Shiro Fujishiro ◽  
Harold L. Gegel
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
Titanium Alloys ◽  
Growth Kinetics ◽  
Stoichiometric Composition ◽  
Good Potential ◽  
Alpha Titanium ◽  
Cold Rolled ◽  
Kinetics Of ◽  
Thermal Stability Of

Ordered-alpha titanium alloys having a DO19 type structure have good potential for high temperature (600°C) applications, due to the thermal stability of the ordered phase and the inherent resistance to recrystallization of these alloys. Five different Ti-Al-Ga alloys consisting of equal atomic percents of aluminum and gallium solute additions up to the stoichiometric composition, Ti3(Al, Ga), were used to study the growth kinetics of the ordered phase and the nature of its interface.The alloys were homogenized in the beta region in a vacuum of about 5×10-7 torr, furnace cooled; reheated in air to 50°C below the alpha transus for hot working. The alloys were subsequently acid cleaned, annealed in vacuo, and cold rolled to about. 050 inch prior to additional homogenization

Growth Kinetics of Quantum Size ZnO Particles

1998 ◽  
Vol 536 ◽  
Author(s):  
E. M. Wong ◽  
J. E. Bonevich ◽  
P. C. Searson
Keyword(s):  
Growth Kinetics ◽  
Ostwald Ripening ◽  
Chemical Potential ◽  
Colloidal Suspensions ◽  
Green Emission ◽  
Blue Shift ◽  
Constant Current ◽  
Mass Model ◽  
Zno Particles ◽  
Kinetics Of

AbstractColloidal chemistry techniques were used to synthesize ZnO particles in the nanometer size regime. The particle aging kinetics were determined by monitoring the optical band edge absorption and using the effective mass model to approximate the particle size as a function of time. We show that the growth kinetics of the ZnO particles follow the Lifshitz, Slyozov, Wagner theory for Ostwald ripening. In this model, the higher curvature and hence chemical potential of smaller particles provides a driving force for dissolution. The larger particles continue to grow by diffusion limited transport of species dissolved in solution. Thin films were fabricated by constant current electrophoretic deposition (EPD) of the ZnO quantum particles from these colloidal suspensions. All the films exhibited a blue shift relative to the characteristic green emission associated with bulk ZnO. The optical characteristics of the particles in the colloidal suspensions were found to translate to the films.

Growth kinetics of boride layers formed on GGG 40.3 ductile iron

2016 ◽  
Vol 58 (5) ◽  
pp. 418-421
Author(s):  
Fatma Ünal ◽  
Ahmet Topuz
Keyword(s):  
Growth Kinetics ◽  
Ductile Iron ◽  
Kinetics Of

scholarly journals Study of deposition parameters and growth kinetics of ZnO deposited by aerosol assisted chemical vapor deposition

RSC Advances ◽  
2021 ◽  
Vol 11 (30) ◽  
pp. 18493-18499
Author(s):  
Sergio Sánchez-Martín ◽  
S. M. Olaizola ◽  
E. Castaño ◽  
E. Urionabarrenetxea ◽  
G. G. Mandayo ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Growth Kinetics ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Kinetics Analysis ◽  
Deposition Parameters ◽  
Kinetics Of

Impact of deposition parameters, microstructure and growth kinetics analysis of ZnO grown by Aerosol-assisted Chemical Vapor Deposition (AACVD).

scholarly journals Morphology, energetics and growth kinetics of diphenylalanine fibres

2021 ◽  
Author(s):  
Phillip Mark Rodger ◽  
Caroline Montgomery ◽  
Giovanni Costantini ◽  
Alison Rodger
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Growth Kinetics ◽  
Dynamics Simulations ◽  
Kinetics Of

The formation and stability of diphenylalanine fibres are studied by combining molecular dynamics simulations with microscopy and spectroscopy experiments, quantitatively detailing their morphology, energetics and growth kinetics.

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