Effect of microstructure and mechanical properties on wear behavior of plasma-sprayed Cr2O3-YSZ-SiC coatings. Issue 5 (1st April 2019)

• Record Type: Journal Article
• Authors: Hashemi, S.M.; Parvin, N.; Valefi, Z.
• Is Part Of: Ceramics international. Volume 45:Issue 5(2019)
• Page Start: 5284
• Page End: 5296
• Publication Date: 2019-04-01
• Subjects: Ball-on-disk wear -- Cr2O3-YSZ-SiC -- Plasma spray coating -- Ceramic matrix composite -- Multimodal/nano -- Mechanical properties; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2018.11.226
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: In this study, the microstructure and mechanical properties of the atmospheric plasma-sprayed Cr2 O3 (C), Cr2 O3 -20YSZ (CZ), and Cr2 O3 -20YSZ-10SiC (CZS) coatings were evaluated and also compared with each other, so as to explain the coatings wear behavior. Microstructural evaluations included X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) equipped with energy dispersive X-ray spectroscopy (EDX) and porosity measurements. Mechanical tests including bonding strength, fracture toughness, and micro-hardness tests were used to advance our understanding of the correlation between the coatings properties and their wear behavior. The sliding wear test was conducted using a ball-on-disk configuration against an alumina counterpart at room temperature. Addition of multimodal YSZ and subsequent SiC reinforcements to the Cr2 O3 matrix resulted in an increase in the fracture toughness and Vickers micro-hardness, respectively. It was found that the composite coatings had comparable coefficients of friction with pure Cr2 O3 coatings. When compared with the C coating, the CZ and CZS composite coatings with higher fracture toughness exhibited superior wear resistance. Observation of the wear tracks of the coatings indicated that the lower wear rates of the CZ and CZS coatings were due to the higher plastic deformation of the detached materials. In fact, improvement in the wear resistance of the composite coatings was attributed to a phase transformation toughening mechanism associated with tetragonal zirconia which created more ductile tribofilms during the wear test participated in filling the pores of coatings.