Martensitic Iron-Carbon-Boron Alloy Electrodeposit with Improved Mechanical Properties

Abstract

Iron-carbon-boron (Fe-C-B) alloy films have been prepared by cathodic deposition from an aqueous solution containing iron(II) chloride hydrate, malic acid, and dimethylamineborane (DMAB). Effects of DMAB concentration on the structural and mechanical characteristics were investigated with an analysis of evolved gas, X-ray diffraction, X-ray photoelectron spectroscopy, and measurements of Vickers hardness number, fracture toughness, and wear volume. The Fe-C-B alloy films had a martensitic structure with body-centered tetragonal lattice with interstitial carbon and boron atoms, and showed high Vickers hardness number of around 700 by solid solution hardening, irrespective of DMAB concentration. The Fe-0.96 mol % C-0.64 mol % B alloy film showed excellent fracture toughness and decreased wear volume, compared with those for Fe-C alloy films. The improvement in fracture toughness and wear resistance was achieved by decreasing the content of oxygen impurity in the films. © 2002 The Electrochemical Society. All rights reserved.

Electrodeposition of Iron with Co-deposition of Carbon: On the Nature of Nanocrystalline Fe-C Coatings

“…More recently, the intended co-deposition of other elements (e.g., tungsten, nickel, phosphorous and zinc) from advanced electrolytes inspired a revival of the original interest in iron-based coatings [4]. Of particular interest is the co-deposition of carbon and iron, and iron-carbon (Fe-C) coatings have been synthesized not only by electrochemical deposition [5][6][7][8][9][10][11][12][13], but also by physical vapor deposition [14][15][16][17]. Although different morphologies and structures of Fe-C coatings ranging from amorphous to crystalline and different carbon concentrations are reported for the various deposition processes, all Fe-C coatings possess very high hardness, being similar to the hardness of martensite in steels.…”

“…In addition to the type of electrolyte and the process parameters, like current density and temperature, both nucleation and growth of electrodeposits are further affected by 60 the nature of the substrate, which influences the size, shape, crystallographic orientation of the grains, and consequently, resulting properties of the coatings. Previous studies dedicated to electrochemical deposition of Fe-C coatings refer to an iron-sulfate bath with the addition of a small amount of carbon-containing organic acids [5][6][7][8][9][10][11][12][13]. The type of such organic additives has been found to determine not only the possible amount of co-deposited carbon but also the macroscopic appearance as well as the topography, morphology, and associated properties of the Fe-C coatings [7,12,13].…”

Electrodeposition of Fe-C Alloys from Citrate Baths: Structure, Mechanical Properties, and Thermal Stability

“…Using the equation by Niihara [20] for median cracks obtained from Vickers indentation, an estimated fracture toughness of 3.8 MPa m 0.5 is obtained from the measured crack lengths of both A50 and B50 samples, whereas for A65 3.2 MPa m 0.5 is determined. for electrodeposited Fe-C alloys in the literature [3,4,10,14,15] could not be found, but a tetragonal distortion with a small c/a ratio cannot be excluded due to the limited angular resolution of the diffraction data. The 2D diffraction patterns clearly reveal the preferred orientation of (211) planes perpendicular to the growth direction ( Figure 3a).…”

“…Finally, the electrodeposition of ternary alloys including Fe-C has been studied. However, these investigations are restricted to the addition of another element of the iron group (nickel [7] or cobalt [13]) and the elements phosphorous and boron [14,15]. The codeposition of hydrogen is inherent to the electrodeposition of iron and its alloys in general [16], but was shown to be significantly enhanced in the case of Fe-C alloy deposition [17].…”

Kinetics study and influence of water-soluble polymer on the electrodeposition of iron from a citrate-chloride electrolyte on the basis of Fe(III)

“…Therefore, we investigated the influence of electrolyte stirring on the kinetics of partial electrochemical processes. Figure 2 shows the effect of electrolyte agitation by a magnetic stirrer (60 rpm) on the partial polarization curves of electrode processes (1), (2), and (3).…”