A comparative study on microstructure and tribological characteristics of Mo2FeB2/WC self-lubricating composite coatings with addition of WS2, MoS2, and h-BN. (January 2023)

• Record Type: Journal Article
• Authors: Zhang, Hao; Pan, Yingjun; Zhang, Yang; Lian, Guofu; Cao, Qiang; Que, Linzhi
• Is Part Of: Materials & design. Volume 225(2023)
• Publication Date: 2023-01
• Subjects: Laser cladding -- Mo2FeB2/WC self-lubricating coating -- WS2, MoS2, and h-BN addition -- Wear rate -- Wear mechanism; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2022.111581
• Languages: English
• ISSNs: 0264-1275

Abstract

Graphical abstract: Highlights: Mo2 FeB2 /WC self-lubricating coatings were fabricated via laser cladding. Microstructure of Mo2 FeB2 /WC coating was refined by the addition of h-BN. Tribological properties of Mo2 FeB2 /WC self-lubricating coatings were revealed. Abstract: To enhance the tribological properties and service life of Mo2 FeB2 /WC coatings, self-lubricating composite coatings with addition of WS2, MoS2, and h-BN were fabricated using laser cladding. The morphology, microstructure, microhardness, and tribological properties of the Mo2 FeB2 /WC self-lubricating composite coatings were investigated. The results indicated that the addition of WS2, MoS2, and h-BN increased the bonding properties between the coating and substrate. Sulfides and nitrides were found in the self-lubricating composite coatings; the Mo2 FeB2 /WC/h-BN coating exhibited a fine dendritic structure. The microhardnesses of the Mo2 FeB2 /WC, Mo2 FeB2 /WC/WS2, Mo2 FeB2 /WC/MoS2, and Mo2 FeB2 /WC/h-BN coatings were 1591.3 HV0.5, 1345.6 HV0.5, 1378.9 HV0.5, and 1415.3 HV0.5, respectively. After the addition of WS2, MoS2, and h-BN, the coefficients of friction decreased by 9.09%, 15.15%, and 30.30%, respectively; the corresponding wear rates decreased by 10.80%, 19.03%, and 30.97%, respectively. The self-lubricating phases significantly improved the tribological properties of the Mo2 FeB2 /WC coating. The main wear mechanisms of the Mo2 FeB2 /WC coating were adhesive and mild oxidative wear; the wear mechanisms after the addition of WS2, MoS2, and h-BN were abrasive and oxidative wear. The wear debris was powder-like for the Mo2 FeB2 /WC/WS2 and Mo2 FeB2 /WC/MoS2 coatings and flake-like for the Mo2 FeB2 /WC/h-BN coating. The lubricating transfer film caused an improvement in the tribological properties.