Room- and high temperature Wear Resistance of MCrAlY Coatings Deposited by Detonation Gun (D-gun) and Supersonic Plasma Spraying (SSPS) Techniques

Mehmet Kilic,Dervis Ozkan,Abdullah Cahit Karaoglanli,Mustafa Sabri Gok

doi:10.3390/coatings10111107

Abstract

In this study, CoNiCrAlY metallic coatings were deposited on an Inconel 718 nickel-based superalloy substrate material using the detonation gun (D-gun) and supersonic plasma spraying (SSPS) techniques. The microstructural and mechanical properties in addition to their room and high temperature wear behavior of the produced coatings were evaluated. The wear tests were performed at room temperature (rt), 250 and 500 °C using 2N and X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS) analyses of the worn coatings were performed to assess their wear performance. The coatings produced with D-gun process exhibited higher hardness and lower porosity (550 ± 50 HV0.25 hardness and 1.2 ± 1.0% porosity) than SSPS coatings (with 380 ± 30 HV0.25 hardness and 1.5 ± 1.0% porosity) which resulted in better room- and high temperature wear performance for D-gun coatings. The worn surfaces of both coatings exhibited formation of tribological layers and superficial microstructural changes by varying temperature and load conditions. Increasing load and temperature resulted in increased wear loss whereas increasing temperature resulted in reduced COF values for both coatings.

Highlights

Thermal spray coatings are widely used as overlay coatings to improve the wear, oxidation and corrosion resistance of engineering materials as a surface modification technique [1,2]
Of metallic bond coated coatings with content coefficient the samples with theCoNiCrAlY
supersonic plasma spraying (SSPS) technique arewere givenproduced in Figure on superalloy substrate material by using

Summary

Introduction

Thermal spray coatings are widely used as overlay coatings to improve the wear, oxidation and corrosion resistance of engineering materials as a surface modification technique [1,2]. Literature showed that the generally used thermal spray techniques for depositing metallic bond coatings are atmospheric plasma spraying (APS), vacuum plasma spraying (VPS), high-velocity oxygen fuel (HVOF) and cold gas dynamic spraying (CGDS) [8,9,10,11]. MCrAlY metallic materials have been developed by considering high-temperature damage like oxidation and corrosion to protect the substrate material [12]. Co or combination both elements) is widely used for turbine blades and vanes of gas turbine engines to provide surface protection [13,14]. MCrAlY-type coatings are widely applied in the form of NiCrAlY, NiCoCrAlY and CoNiCrAlY on nickel-based superalloy substrates. CoNiCrAIY alloys are commonly used as a metallic bond coating layer in thermal barrier coatings (TBCs) due to its Coatings 2020, 10, 1107; doi:10.3390/coatings10111107 www.mdpi.com/journal/coatings

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