Mechanical and microstructural properties of NiCrFeSiBC/Cr₃C₂ composite coatings – part I

Abstract

NiCrFeSiBC/Cr 3 C 2 composite coatings were developed on to GrA1 boiler steel by high velocity oxy fuel spray process. The aim was to develop the novel composite coating by finding optimum concentration of Cr 3 C 2 in NiCrFeSiBC matrix, which further possesses the superior solid particle erosion resistance. The mechanical and microstructural properties of the developed coatings were critically examined. The as sprayed coatings were characterised by X-ray diffraction, SEM/ energy dispersive spectroscopy analyses. The coatings exhibited characteristic splat-like morphology with the presence of micropores, unmelted and semimelted particles and inclusions. The adhesion strength of the developed coatings was also determined. The physical properties like surface roughness, porosity and microhardness of the as sprayed coatings have also been reported. The blending resulted into the formation of composite-like coatings where, the Cr 3 C 2 phase was nearly uniformly distributed into the NiCrFeSiBC matrix. The results have been discussed with respect to the existing literature.

Comparison of Ni-Based Self-Fluxing Remelted Coatings for Wear and Corrosion Applications

“…The phase composition determined by means of XRD analysis consists, in both cases, of γ-Ni/Ni 3 B solid solution and further phases like CrB and Cr 6 Ni 16 Si 7 . Similar γ-Ni/Ni 3 B phases were already previously reported in the literature [21][22][23]. Corroborating the XRD with the EDX spot analysis, the matrix marked with A in Figure 5a,b consists of the γ-Ni/Ni 3 B phase, the darker region marked with B shows the primary crystals of CrB, while the lighter region of C represents the Cr 6 Ni 16 Si 7 .…”

Caracterización de recubrimientos NiCrBSiMo depositados por rociado térmico por flama usando diferentes parámetros de depósito

“…It is worth nothing that the use of small nozzles contributes to reduce the porosity by about 4 times (from 12.1% to 2.7%) and increase the hardness from 900 to 1264 HV. Similar porosity (Miguel et al, 2003;Shrestha et al, 2005;Yu et al, 2013;Singh and Kaur, 2016;Wen et al, 2017) and hardness (González et al, 2007a;González et al, 2007b;Singh and Kaur, 2016) values have been reported for thermally sprayed Ni-based coatings. However, the porosity content obtained in the present study for C3 and C4 conditions (2.7% in average), is lower compared to those reported for as-sprayed selffluxing coatings deposited by flame and plasma spraying (Higuera Hidalgo et al, 2001;Kim et al, 2003;Planche et al, 2005;Culliton et al, 2013;Bergant et al, 2014).…”

Tribological Behaviour of Plasma and HVOF-sprayed NiCrSiBFe Coatings

“…Adhesive/delamination wear mechanism observed for flame remelted supersonic plasma-sprayed NiCrBSi powder with 30% Mo coating under dry sliding wear test [11]. Cr 3 C 2 addition in NiCrBSi powder produced excellent wear resistance coating and bond strength [12,13]. Plasma-sprayed NiCrBSi powder with 4% graphite addition improved the erosion resistance and microhardness [14].…”

“…For significant interpretation, the selection of the most suitable test based on the mechanical system and operating condition is essential [22]. Some pieces of the literature have studied the tribological behaviour of nickel and WC-based coating under various test such as dry sliding wear test [23][24][25], abrasive wear test [26], solid particle erosion test [13,27], cavitation erosion test [23,28], and slurry jet liquid impingement test [29].…”