Growth Kinetics of CoB–Co2B Layers Using the Powder-Pack Boriding Process Assisted by a Direct Current Field

AbstractNew results about the growth kinetics of CoB–Co2B layers developed at the surface of CoCrMo alloy using the powder-pack boriding process assisted by a direct current field (PBDCF) were estimated in this work. The PBDCF was conducted at temperatures of 1048 – 1148 K with different exposure times for each temperature, whereas the growth kinetics of the cobalt boride layers was modelled using a system of two differential equations. In addition, indentation properties such as hardness, Young’s modulus and residual stresses were estimated along the depth of the borided CoCrMo surface. The growth kinetics of the cobalt boride layers developed by PBDCF indicated that thicker boride layers were formed on the material’s surface which was in contact to the current field at the anode, in contrast to the surface exposed at the cathode. The kinetics of cobalt boride layers were compared with those obtained by conventional powder-pack boriding process.

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Kinetics of the Boride Layers Obtained on AISI 1018 Steel by Considering the Amount of Matter Involved

Coatings ◽

10.3390/coatings11020259 ◽

2021 ◽

Vol 11 (2) ◽

pp. 259 ◽

Cited By ~ 1

Author(s):

Pablo A. Ruiz-Trabolsi ◽

Julio Cesar Velázquez ◽

Carlos Orozco-Álvarez ◽

Rafael Carrera-Espinoza ◽

Jorge A. Yescas-Hernández ◽

...

Keyword(s):

Sample Size ◽

Growth Kinetics ◽

Duration Of Treatment ◽

Solid Diffusion ◽

Treatment Conditions ◽

Wear And Corrosion ◽

Different Diameters ◽

Boriding Process ◽

Kinetics Of ◽

Cylindrical Samples

Boride layers are typically used to combat the wear and corrosion of metals. For this reason, to improve our knowledge of the boriding process, this research studied the effect of the size of the treated material on the kinetics of the growth of the boride layers obtained during a solid diffusion process. The purpose was to elucidate how the layers’ growth kinetics could be affected by the size of the samples since, as the amount of matter increases, the amount of energy necessary to make the process occur also increases. Furthermore, the level of activation energy seems to change as a function of the sample size, although it is considered an intrinsic parameter of each material. Six cylindrical samples with different diameters were exposed to the boriding process for three different exposure times (1.5, 3, and 5 h). The treatment temperatures used were 900, 950, and 1000 °C for each size and duration of treatment. The results show that the layer thickness increased not only as a function of the treatment conditions but also as a function of the sample diameter. The influence of the sample size on the growth kinetics of the boride layers is clear, because the growth rate increased even though the treatment conditions (time and temperature) remained constant.

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Nucleation rates and the kinetics of particle growth I. The pure birth process

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1964.0013 ◽

1964 ◽

Vol 277 (1369) ◽

pp. 155-166 ◽

Cited By ~ 28

Keyword(s):

Differential Equations ◽

Chemical Reaction ◽

Growth Kinetics ◽

Particle Growth ◽

Growth Data ◽

Birth Process ◽

Irreversible Chemical Reaction ◽

Growth Laws ◽

Infinite Set ◽

Kinetics Of

A model of particle growth kinetics in a condensing system is investigated in which the mechanism is presumed to be an irreversible chemical reaction which proceeds at the particle-atm osphere interface. General growth laws for the assembly of particles are derived from the resulting infinite set of differential equations and tested against growth data on sulphur hydrosols. The relation between the model and the well-known pure birth process of mathematical statistics is emphasized.

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Computer simulation of monolayer growth kinetics of Fe 2 B phase during the paste-boriding process: Influence of the paste thickness

Applied Surface Science ◽

10.1016/j.apsusc.2006.01.011 ◽

2006 ◽

Vol 253 (2) ◽

pp. 757-761 ◽

Cited By ~ 33

Author(s):

M. Keddam

Keyword(s):

Computer Simulation ◽

Growth Kinetics ◽

Monolayer Growth ◽

Boriding Process ◽

Kinetics Of

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The boriding process in CoCrMo alloy: Fracture toughness in cobalt boride coatings

Surface and Coatings Technology ◽

10.1016/j.surfcoat.2014.07.092 ◽

2014 ◽

Vol 260 ◽

pp. 362-368 ◽

Cited By ~ 27

Author(s):

I. Campos-Silva ◽

D. Bravo-Bárcenas ◽

H. Cimenoglu ◽

U. Figueroa-López ◽

M. Flores-Jiménez ◽

...

Keyword(s):

Fracture Toughness ◽

Cocrmo Alloy ◽

Boride Coatings ◽

Cobalt Boride ◽

Cobalt Boride Coatings ◽

Boriding Process

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Effect of boron paste thickness on the growth kinetics of polyphase boride coatings during the boriding process

Applied Surface Science ◽

10.1016/j.apsusc.2005.04.022 ◽

2006 ◽

Vol 252 (6) ◽

pp. 2396-2403 ◽

Cited By ~ 26

Author(s):

I. Campos ◽

R. Torres ◽

O. Bautista ◽

G. Ramírez ◽

L. Zúñiga

Keyword(s):

Growth Kinetics ◽

Boride Coatings ◽

Boriding Process ◽

Kinetics Of

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Interface kinetics of combustion–diffusion bonding of Ni3Al/Ni and TiAl/Ti under direct current field

Journal of Materials Science ◽

10.1007/s10853-012-6869-1 ◽

2012 ◽

Vol 48 (3) ◽

pp. 1268-1274 ◽

Cited By ~ 7

Author(s):

S. P. Chen ◽

F. Dong ◽

W. H. Fan ◽

Q. S. Meng ◽

Zuhair A. Munir

Keyword(s):

Direct Current ◽

Diffusion Bonding ◽

Current Field ◽

Interface Kinetics ◽

Kinetics Of

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Dimensional analysis in the growth kinetics of FeB and Fe2B layers during the boriding process

International Journal of Microstructure and Materials Properties ◽

10.1504/ijmmp.2007.012940 ◽

2007 ◽

Vol 2 (1) ◽

pp. 73 ◽

Cited By ~ 1

Author(s):

R. Torres ◽

I. Campos ◽

G. Ramirez ◽

O. Bautista ◽

J. Martinez

Keyword(s):

Dimensional Analysis ◽

Growth Kinetics ◽

Boriding Process ◽

Kinetics Of

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Effects of direct current field on powder-packed boriding process on martensitic stainless steel AISI 420

Archives of Metallurgy and Materials ◽

10.2478/v10172-012-0087-3 ◽

2012 ◽

Vol 57 (3) ◽

pp. 799-804 ◽

Cited By ~ 3

Author(s):

L. Angkurarach ◽

P. Juijerm

Keyword(s):

Stainless Steel ◽

Direct Current ◽

Martensitic Stainless Steel ◽

Boride Layer ◽

Current Field ◽

Aisi 420 ◽

Double Phase ◽

Steel Aisi ◽

Boriding Process ◽

Stainless Steel Aisi

The effects of direct current field on a powder-packed boriding process on a martensitic stainless steel AISI 420 have been investigated at a temperature of 900°C for about 2–6 hr. A powder-packed boriding process without direct current field (conventional powder-packed boriding process, PB) is a reference as compared to the powder-packed boriding process with applied current densities (PB-DC) of 60-170 mA/cm2. The microstructure and the presence of boride layers of PB and PB-DC were characterized using optical microscope and X-ray diffraction (XRD). The hardness values of the boride layer were measured by Vickers microhardness tester. Experimental results show that the direct current filed can enhance the decomposition and chemical reaction in the boriding agent and also drive active free boron ions as well as atoms to diffuse toward the cathode. Therefore, a boron concentration around the specimen at the cathode of PB-DC is higher than that at the anode as well as PB (as a reference). As a consequence, higher boride layer thickness of PB-DC was detected. The double-phase boride layer (FeB and Fe2B) on borided martensitic stainless steel AISI 420 was found both PB and PB-DC. The hardness of the boride layer of about 1800–2000 HV can be observed.

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Diffusional Growth Kinetics of Boride Layers at the 13% Cr Steel Interface with Amorphous Boron

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.263.183 ◽

2007 ◽

Vol 263 ◽

pp. 183-188 ◽

Cited By ~ 2

Author(s):

Vasil I. Dybkov

Keyword(s):

Experimental Data ◽

Differential Equations ◽

Growth Kinetics ◽

Reaction Times ◽

Average Content ◽

Amorphous Boron ◽

Diffusional Growth ◽

Fe2b Phase ◽

Linear Differential ◽

Kinetics Of

Two borides FeB and Fe2B were found to form as separate layers at the interface between a 13% Cr steel and boron at 850-950 oC and reaction times up to 12 h. The chromium distribution within the boride layers is rather irregular. Its average content is 8 at. % in the FeB layer and 9 at. % in the Fe2B layer. Both layers are characterized by a pronounced texture. The strongest reflections are {002} and {020} for the orthorhombic FeB phase and {002} for the tetragonal Fe2B phase. Diffusional growth kinetics of boride layers are close to parabolic and can alternatively be described by a system of two non-linear differential equations, producing a good fit to the experimental data.

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