Sliding wear performance of high-velocity oxy-fuel spray Al₂O₃/TiO₂ and Cr₂O₃ coatings

Abstract

High-velocity oxy-fuel (HVOF) spray ceramic oxide coatings have immense potential in industrial applications. However, they are not widely used yet due to the lack of an adequate scientific database created after testing these coatings for specific industrial applications. Two such ceramic coating powders, Al 2 O 3 + (40%)TiO 2 and Cr 2 O 3 , were deposited on AISI 309 SS stainless steel by the HVOF spray technique, in order to enhance its wear resistance. This stainless steel is used in many components of thermal power plants in India, where it suffers one or more types of wear. The as-sprayed coatings were characterized by XRD and SEM analyses. Subsequently, the sliding wear behaviours of the uncoated, HVOF spray Al 2 O 3 + (40%)TiO 2 and Cr 2 O 3 coated AISI 309 SS were investigated according to ASTM standard G99-03 on a pin-ondisc wear test rig. Cumulative wear rate and coefficient of friction (μ) were calculated for the coated as well as the uncoated specimens for 30, 50, and 70 N normal loads at a constant sliding velocity of 1 m/s. Some of the worn-out surfaces were characterized by SEM analysis. Both the as-sprayed coatings exhibited typical splat morphology of a thermal spray process. The XRD analysis indicated the formation of Al 2 O 3 and TiO 2 phases for the Al 2 O 3 + (40%)TiO 2 coating, and Cr 2 O 3 phase for the Cr 2 O 3 coating. It has been concluded that HVOF spray Al 2 O 3 + (40%)TiO 2 and Cr 2 O 3 coatings can be useful in minimizing the wear problem of AISI 309 SS. These coatings were found to be successful in retaining their surface contact with the substrate after the wear tests. The HVOF spray Cr 2 O 3 coating can be recommended as a slightly better choice to reduce the wear of AISI 309 SS in comparison with the Al 2 O 3 + (40%)TiO 2 coating.

Comparative Studies on Mechanical Properties and Corrosion Rate of Nickel Chromium Carbide (Cr3C2-NiCr) Coated on Inconel 600, 625, 718 Specimen

“…In well-designed tribological systems, the removal of material is usually a very slow process but it is very steady and continuous [9]. Wear related failure of machinery components counts as one of the major reasons for inefficient working of machines in a variety of engineering applications [10]. Serviceable engineering components not only rely on their bulk material properties but also on the design and characteristics of their surface [11].…”

Influence of the Titania Content on the Microstructure and Properties of Plasma Sprayed Alumina-Titania Coatings

“…The very good combination of mechanical and thermal properties of oxide-based coatings makes them a desirable coating working in harsh conditions that involve mechanical and corrosive factors. Nowadays, the most common methods for a ceramic coating deposition are an atmospheric plasma spraying (APS) [1] and the high-velocity oxygen fuel (HVOF) thermal spraying [2]. The APS sprayed ceramic coatings are widely applied to structural materials and various machine parts in order to improve wear, oxidation and corrosion resistance [3].…”

Depositing Fe-C-Cr based Hardfacing Alloys on Steel Substrate for Enhancement in Wear Resistance

“…These wear and corrosion associatedissues can be reduced primarily by utilizing costly wear resistant materials,superior than the existing low cost ones or by employment of certain surface alteration methods on the existing materials in order to improve its wear resistance [5]. Generallywear takes place on the surfaces in contact, subsequently the utilization of the surface alteration techniques on existing materials is more reasonable and inexpensive than utilizing costly or superior wear resistant materials.During the design of an engineering component the properties of the materials from which it is fabricated should not be ignored as they have a considerable effect on its functioning as well as the service life [6].…”