Open AccessInvestigation into corrosion and wear behaviors of laser-clad coatings on Ti6Al4V
Author(s) -
Yunlong Zhang,
Jun Li,
Yunqiang Jiang,
Danning Kang,
Yongfei Juan,
Zan Lü
Publication year - 2020
Publication title -
materials research express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.383
H-Index - 35
ISSN - 2053-1591
DOI - 10.1088/2053-1591/ab6a53
Subject(s) - materials science , corrosion , coating , dissolution , metallurgy , immersion (mathematics) , alloy , cladding (metalworking) , high entropy alloys , composite material , chemical engineering , mathematics , pure mathematics , engineering
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.