Abstract
Wear resistant coatings that comply with non-toxic environment goals are highly desirable. Cr3C2–NiCr is a promising alternative to the toxic, ‘Co’- containing WC–Co coatings to mitigate wear. The purpose of this study was to examine the suitability of Cr3C2–NiCr coatings for automotive brake disc application by systematically investigating their dry sliding wear behavior at different test conditions. Therefore, High Velocity Air Fuel (HVAF) and High Velocity Oxy Fuel (HVOF) were employed to deposit Cr3C2–NiCr coatings. The powder feedstock and as-deposited Cr3C2–NiCr coatings were characterized for their microstructure and phase composition using SEM and XRD. Mechanical properties (hardness, fracture toughness), porosity and surface topography of the as-deposited coatings were evaluated. The coatings were subjected to sliding wear tests at different normal loads (5 N, 10 N and 15 N) using alumina ball as the counter surface. Coefficient of friction (CoF) evolution of HVAF and HVOF deposited coatings, along with their wear performance, was obtained for different normal load conditions. The wear performance ranking of HVAF and HVOF processed coatings was influenced by the test conditions, with HVAF coatings demonstrating better wear resistance than HVOF coatings at harsh test conditions and the HVOF coatings performing better under mild wear test conditions. Detailed post-wear analysis of worn coatings, the alumina ball counter-body and the resulting debris was performed to reveal the degradation mechanisms at different test conditions. Findings from this work provide new insights into the desirable microstructural features to mitigate wear, which can be further exploited to deposit wear-resistant coatings.
Highlights
Durability and performance of several engineering components is often compromised due to wear-related degradation [1,2]
The particle-like shape of Cr3C2 indicates that High velocity oxy-fuel (HVOF) spraying too was unable to accomplish complete melting of carbides in the feedstock during flight
The asdeposited coatings were subjected to ball-on-disc tests at mild (5 N, 10 N) and harsh (15 N) sliding wear conditions
Summary
Durability and performance of several engineering components is often compromised due to wear-related degradation [1,2]. Ceramic and cermet-based protective coatings are often employed to combat wear [3e7]. Among the existing list of coating compositions to mitigate wear, WCeCo coatings possess superior wear resistance [8e10] and are widely used in applications such as automotive brake discs [4]. ‘Co’ is known to be carcinogenic [11], which exposes the operators and end-users to health hazard [12]. ‘Co’ is not an economically viable and sustainable option due to its limited availability worldwide [13]. Co-free coating compositions that possess adequate wear resistance are highly desirable in order to comply with sustainability and non-toxicity standpoints
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
