Open AccessMicrostructure and properties of ZrO2/Ni3Al-Ni3Al double-layer coating on stainless steel prepared by powder sintering one-step forming process
Author(s) -
Xinxing Li,
Zhiliang Yang,
Hongxia Wang,
Lin Li,
Ren Nai-Fei
Publication year - 2021
Publication title -
materials research express
Language(s) - English
Resource type - Journals
ISSN - 2053-1591
DOI - 10.1088/2053-1591/ac386d
Subject(s) - materials science , microstructure , coating , diffractometer , sintering , layer (electronics) , scanning electron microscope , metallurgy , substrate (aquarium) , indentation hardness , oxide , composite material , oceanography , geology
ZrO 2 /Ni 3 Al-Ni 3 Al double-layer coating on stainless steel was prepared by powder sintering one-step forming process. The surface-interface morphologies, chemical element distribution and phase compositions of the coatings before and after thermal oxidation or hot corrosion were analyzed using scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and X-ray diffractometer (XRD). The microstructure of the coating was Ni 3 Al matrix with dispersed ZrO 2 particles, which was pure and compacted. The Ni 3 Al intermediate layer compactly formed between stainless steel substrate and ZrO 2 /Ni 3 Al composite coating, with good metallurgical bonding interfaces. The ZrO 2 /Ni 3 Al-Ni 3 Al double-layer coating exhibited a relatively high outmost microhardness of about 500 HV, and then gradually decreased from the coating to the substrate. When thermal oxidized or hot corroded at 1050 °C, a mixed oxide layer of NiO, Al 2 O 3 and NiAl 2 O 4 formed on the coating surface, which effectively acted as a diffusion barrier for oxygen and corrosive substances, and thus demonstrated the good protective effect of ZrO 2 /Ni 3 Al coating.