Synthetic Effect of Cr and Mo Elements on Microstructure and Properties of Laser Cladding NiCrxMoy Alloy Coatings

Abstract

NiCr x Mo y (x = 1, 1.5; y = 0, 0.1, 0.3) alloy coatings were prepared on the Q235 substrate by laser cladding under the protection of argon. The phase composition, microstructure, corrosion behavior, and mechanical properties of the NiCr x Mo y alloy coatings were investigated using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, electrochemical tests, X-ray photoelectron spectroscopy, microhardness, and nanoindentation tests. As the Cr content increased, the phase composition of the coatings changed from a single face-centered cubic (FCC) structure to a dual-phase structure coexisting with body-centered cubic (BCC) and FCC structures, while the addition of Mo promoted the precipitation of σ phase. The appearance of a homogeneous dual-phase structure and some amount of σ phase played a positive role in the corrosion resistance of NiCr x Mo y coatings. Cr 3+ ions and Mo 6+ ions in the passive film enhanced the stability of the coatings. The nanoindentation tests showed that the nanohardness (6.71 GPa) and elastic modulus (184.40 GPa) of BCC phase were higher than those of the FCC phase (5.19 GPa and 155.26 GPa, respectively). Overall, the BCC phase and σ phase improved the mechanical properties of the coatings.

RETRACTED: The Effect of Vacuum Annealing Temperature on the Properties of AlCrTiSiN Coating Prepared by Arc Ion Plating

“…The shear strength and compressive strength of the coating can be effectively improved by increasing the Al content in the coating, and the overall mechanical properties can be further improved [11]. Doping Si and Cr elements into the coating can effectively improve the mechanical, friction, and high temperature resistance properties of the coating [12,13]. Chang et al [14] prepared AlTiN and AlTiSiN coatings by an acathodic arc deposition system and compared them.…”