Microstructure characterisation and wear properties of arc sprayed NiB containing amorphous coatings

Abstract Two kinds of cored wires were used to deposit coatings containing amorphous phase and nanocrystalline grains by arc spraying. The microstructure characteristics of the coatings were conducted by scanning electron microscopy (SEM), transmission electron microscopy (TEM), electron probe micro-analyzer (EPMA) and X-ray diffraction (XRD). The microstructures of the both coatings had lamellar morphologies. Both coatings consisted of Fe rich matrix and several kinds of borides. The Fe rich matrix had a majority amorphous phase regions with a fraction of nanocrystalline grains. The coatings’ microhardness values for NiB coating is 950 HV(100 g) and for NiB–Cr3C2 coating is 1090 HV(100 g). Compared with the reference sample of Q235 steel, the coatings showed a much higher wear resistance, and the relative wear resistance of the NiB coating is 10 times while the NiB–Cr3C2 coating is 13·3 times higher than that of Q235 steel.

[1]  F. Banhart,et al.  Microstructural evolution of wear-resistant FeCrB and FeCrNiCoB coating alloys during high-energy mechanical attrition , 2008 .

[2]  A. Kobayashi,et al.  Fe-based metallic glass coatings produced by smart plasma spraying process , 2008 .

[3]  J. Murthy,et al.  Microstructure dependent erosion in Cr3C2–20(NiCr) coating deposited by a detonation gun , 2007 .

[4]  A. Inoue,et al.  Super-high strength of over 4000 MPa for Fe-based bulk glassy alloys in [(Fe1-xCox)0.75B0.2Si0.05]96Nb4 system , 2004 .

[5]  S. Poon,et al.  Fe-based bulk metallic glasses with diameter thickness larger than one centimeter , 2004 .

[6]  K. Khor,et al.  Microstructure and composition analysis in plasma sprayed coatings of Al2O3/ZrSiO4 mixtures , 2002 .

[7]  A. Inoue,et al.  Synthesis of Fe–Cr–Mo–C–B–P bulk metallic glasses with high corrosion resistance , 2002 .

[8]  M. Kim,et al.  In situ TEM heating studies on the phase transformation of metastable phases in Fe–Cr–B alloy spray coatings , 2001 .

[9]  D. G. McCartney,et al.  Microstructural characterisation of a Ni-Cr-B-C based alloy coating produced by high velocity oxy-fuel thermal spraying , 2001 .

[10]  Anthony G. Evans,et al.  Microstructure, deformation and cracking characteristics of thermal spray ferrous coatings , 1999 .

[11]  M. Vardelle,et al.  Temperature evolution of plasma-sprayed niobium particles impacting on a substrate , 1991 .

[12]  Keiske Kaji,et al.  X-Ray Diffraction Procedures , 1975 .

[13]  B. Vainshtein,et al.  Diffraction of X-rays by chain molecules , 1966 .