Use of microhardness as a simple means of estimating relative wear resistance of carbide thermal spray coatings: Part 2. Wear resistance of cemented carbide coatings

• Published in: Journal of thermal spray technology Vol. 11; no. 4; pp. 482 - 495
• Main Authors: FACTOR, Michael, ROMAN, Itzhak
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 01.12.2002; Springer Nature B.V
• Subjects: Abrasion resistance; Applied sciences; Cemented carbides; Coatings; Cobalt; Contact of materials. Friction. Wear; Exact sciences and technology; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Microhardness; Protective coatings; Tungsten carbide; Wear resistance; Ceramic matrix composite; Scanning electron microscopy; Tungsten carbide; Hardness test; Chromium carbide; Hot spraying; Mechanical properties; Experimental study; Coatings; Cobalt; Spray coating; Microhardness; Chromium alloy; Cemented carbides; Wear resistance; Nickel alloy; Tribology
• ISSN: 1059-9630; 1544-1016
• DOI: 10.1361/105996302770348619

A selection of WC-Co and Cr sub 3 C sub 2 -25%NiCr coatings produced by plasma spray and high velocity oxygen fuel (HVOF) deposition techniques were subjected to various wear tests designed to simulate abrasion, cavitation, sliding, and particle erosion type wear mechanisms. All of the coatings were at least 200 mu m thick and were deposited onto stainless steel substrates. In Part 1 of this contribution, the microstructures of the coatings were characterized and their mechanical properties were assessed using microindentation procedures. In this second part of the article, the behavior of the coatings when subjected to the various wear tests is reported and the utility of microhardness testing as an indication of relative wear resistance is discussed. It is shown that correctly performed, appropriate microhardness measurements are a good indication of abrasion resistance and sliding wear resistance, and also correlate well with cavitation resistance in Cr sub 3 C sub 2 -MCr. The measurements were less useful for predicting erosion resistance for both Cr sub 3 C sub 2 -NiCr and WC-Co, however, and for abrasion resistance when WC-Co was ground against SiC. Here the contribution of micro-mechanisms involving fracturing and brittle failure is greater than that indicated by the coating microhardness, which is essentially a measurement of resistance to plastic deformation under equilibrium conditions.