Al0.25CoCrFeNiV High Entropy Alloy Coating Deposited by Laser Cladding on Stainless Steel

Abstract

This paper studies the microstructure, composition and properties of a Al0.25CoCrFeNiV high entropy alloy coating (HEAC) deposited by laser cladding on austenitic-grade stainless steel. Laser cladding was carried out in an argon atmosphere on a FL-Clad-R-4 laser metal deposition complex with the following parameters: the laser power was 1400 W, the spot diameter was 3 mm, the track displacement was 1.2 mm, and the scanning speed was set to 10 mm/s. A change in the microstructure of the coating after laser cladding was revealed in comparison with as-cast high entropy alloy (HEA) Al0.25CoCrFeNiV. A significant decrease was found in the size of vanadium precipitates, from 20–40 µm in the as-cast state to 1–3 µm after laser cladding. A change in microhardness over the thickness of the coating from 370 HV0.3 at the outer surface to 270 HV0.3 at the boundary with the substrate was established, which may be due to the diffusion of Fe from the stainless steel into the coating material during laser cladding. Despite these features, the resulting coating adheres tightly to the substrate, and has no cracks or other defects, which indicates the possibility of using laser cladding to create coatings from high entropy alloys.

A Novel Superhard, Wear-Resistant, and Highly Conductive Cu-MoSi2 Coating Fabricated by High-Speed Laser Cladding Technique

“…Figure 11 d shows the resistivity of the Cu- x MoSi 2 ( x = 10, 15, 20, 25, 30, wt.%) coating as 0.084 × 10 −6 Ω·m, 0.120 × 10 −6 Ω·m, 0.128×10 −6 Ω·m, 0.144 × 10 −6 Ω·m, and 0.173 × 10 −6 Ω·m. Compared to other copper alloy coating systems [ 4 , 5 , 6 , 7 , 8 , 9 , 10 ] (with a hardness of 684 HV and a resistivity of 3.51 × 10 −6 Ω·m), the coating still maintains a relatively high electrical conductivity. From the conductive mechanism of metals [ 33 ], when an electron wave passes through an ideal crystal lattice at absolute zero, it will propagate unhindered by scattering, and the material is an ideal conductor.…”

“…Compared with the copper substrate, Cu-MoSi 2 coatings exhibit even higher resistance to adhesive wear. [4][5][6][7][8][9][10] (with a hardness of 684 HV and a resistivity of 3.51 × 10 −6 Ω•m), the coating still maintains a relatively high electrical conductivity. From the conductive mechanism of metals [33], when an electron wave passes through an ideal crystal lattice at absolute zero, it will propagate unhindered by scattering, and the material is an ideal conductor.…”

“…Manufacturing copper components with exceptional super hardness, impressive wear resistance, and elevated conductivity is now a necessity. Metal matrix composites (MMCs) comprise the properties of metal matrices (ductility and toughness) and reinforcement phases (high strength and stiffness) [4][5][6][7][8], which enables the superior mechanical and functional properties such as excellent wear resistance, controllable coefficient of thermal expansion, and good thermal shock resistance. However, MMCs normally gives rise to notable dislocation pile-ups and severe stress concentration at grain boundaries [9,10]; extensive research has been relying on manipulating the uniform distribution of the reinforcement phase as an innovative approach for designing the microstructural architecture of MMCs to surmount such a dilemma.…”