Open AccessStrengthening mechanism and properties of Co–WC composite coatings deposited by plasma‐transferred arc welding
Author(s) -
Jiang Qiuyue,
Tian Ye,
Shu Fengyuan,
Zhao Hongyun,
Sun Yiming,
He Wenxiong,
Xu Binshi
Publication year - 2019
Publication title -
micro and nano letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.25
H-Index - 31
ISSN - 1750-0443
DOI - 10.1049/mnl.2018.5545
Subject(s) - materials science , hardfacing , metallurgy , tungsten carbide , scanning electron microscope , carbide , amorphous solid , tungsten , composite material , composite number , eutectic system , coating , welding , alloy , crystallography , chemistry
Cobalt (Co)‐based tungsten carbide (WC) wear‐resistant coatings with different content of WC were prepared on the surface of Q235 low carbon steel by plasma‐transferred arc welding. The properties of the coatings such as strengthening mechanism, microhardness and wear properties were tested by using a metallurgical microscope, scanning electron microscope, energy dispersive spectrometer, X‐ray diffraction, Rockwell hardness tester, and friction wear equipment. The results show that the main reasons for the strengthening of spray welding layer are the solution strengthening formed by α‐Co with supersaturated tungsten (W) and the dispersion strengthening caused by eutectic precipitated carbide and silicide. The proportion of the solid solution of W in α‐Co steadily ranges from 18.00 to 19.59%. The morphologies of rich W‐phase are mainly related to the content of W. With the content of W increasing, the evolution process of the shape is the amorphous form→damascene shape→star‐like shape→the polygon. Amorphous W‐rich phase can be obtained when the content of WC ranges from 20 to 30%, evenly distributed W‐rich phase in the shape of damascene or star can be obtained when the WC content ranges from 30 to 40%, and the polygonal W‐rich phase can be obtained at the percentage of 40–50%.