Investigation into corrosion and wear behaviors of laser-clad coatings on Ti6Al4V

Abstract

TiAlCoCr x FeNihigh-entropy alloys (HEAs) coatings were fabricated on the surface of Ti6Al4V by laser cladding. Their microstructural evolution with the increase in x value (x=0, x=1.0, x=2.0) was investigated in detail. Besides that, the investigation into the effects of the Cr content on their corrosion behaviors and mechanical properties (in terms of hardness and wear resistance) was also carried out comprehensively. The results indicated that two kinds of phases (a solid solution with thehexagonal close-packed (HCP) structureand Ti 2 Ni) were synthesized in the coatings, and the HCP content was gradually increased with the increase in x accompanied with the decrease in Ti 2 Ni content. A HEA coating only composed of single HCP was successfully prepared when x reached 2.0. The electrochemical and immersion tests all confirmed that the coating with x=2.0demonstrated the most excellent corrosion resistance in a0.1 mol·L −1 HCl solution from different aspects including corrosion tendency and corrosion rate without the applied potential, the formation difficult/stability of the passive film and the dissolution rate in the passive state, and corrosion surface morphology. The averagemicrohardness values of the coatings weregraduallyincreasedfrom 656HV 0.2 to 800 HV 0.2 with increasing xfrom 0 to 2.0, which wereabout double that of the substrate (350 HV 0.2 ). Wear resistance of the coatings also exhibited the upward tendency with increasing the x values (0.562 mm 3 at x=2.0, 0.640 mm 3 at x=1.0, 0.641 mm 3 at x=0 and 1.419 mm 3 for the substrate). More Cr addition into the cladding material will contribute to the formation of a HEA coating composed of single HCPwith excellent corrosion and wear resistance.

Wear‐Resistance of High‐Entropy Alloy Coatings and High‐Entropy Alloy‐Based Composite Coatings Prepared by the Laser Cladding Technology: A Review

“…The Ti elements were prone to generate the more common Ti-containing ceramic phases. [55,56] For example, Liu et al [56] prepared CoCrFeMnNiTi x (x = 0, 0.25, 0.5, 0.75, or 1) HEA-LC coatings on a 40Cr substrate. When considering the effect of the dilution ratio, the proportion of iron atoms in the raw material was appropriately reduced.…”

Investigation into the Corrosion Wear Resistance of CoCrFeNiAlx Laser-Clad Coatings Mixed with the Substrate

“…When subjected to wear tests for 180 min in air, the friction coefficient of the coating (0.61) was significantly lower than that of the substrate (1.04), and its wear volume (0.823 ± 0.012 mm 3 ) was reduced by 48% relative to that of the substrate (2.329 ± 0.025 mm 3 ). Zhang et al [41] prepared TiAlCoCr 2 FeNi HEA coating that contained an HCP solid solution by laser cladding on Ti6Al4V. Dry-sliding wear tests performed for 2 h demonstrated that the wear resistance of Ti6Al4V was considerably improved by laser cladding the HEA coating because the wear volume of the coating was approximately 40% that of Ti6Al4V.…”

Archives of Metallurgy and Materials

“…therefore, a suitable surface modification needs to be implemented to protect from undesired material loss. in recent years, many surface modification techniques were attempted to improve the surface properties of titanium alloys such as chemical vapour deposition, physical vapour deposition, micro-arc oxidation, electroplating, laser modification and plasma transferred arc (Pta) process [3][4][5][6][7][8][9]. among these techniques, Pta based surface modification was attracted much attention due to high efficiency, good metallurgical bond, low cost and easy operation.…”