Cavitation Erosion and Sliding Wear Mechanisms of AlTiN and TiAlN Films Deposited on Stainless Steel Substrate

Mirosław Szala,Kamil Pasierbiewicz,Mariusz Kamiński,Mariusz Walczak

doi:10.3390/coatings9050340

Mirosław Szala, Kamil Pasierbiewicz + Show 2 more

Open Access

https://doi.org/10.3390/coatings9050340

Copy DOI

Abstract

The resistance to cavitation erosion and sliding wear of stainless steel grade AISI 304 can be improved by using physical vapor deposited (PVD) coatings. The aim of this study was to investigate the cavitation erosion and sliding wear mechanisms of magnetron-sputtered AlTiN and TiAlN films deposited with different contents of chemical elements onto a stainless steel SS304 substrate. The surface morphology and structure of samples were examined by optical profilometry, light optical microscopy (LOM) and scanning electron microscopy (SEM-EDS). Mechanical properties (hardness, elastic modulus) were tested using a nanoindentation tester. Adhesion of the deposited coatings was determined by the scratch test and Rockwell adhesion tests. Cavitation erosion tests were performed according to ASTM G32 (vibratory apparatus) in compliance with the stationary specimen procedure. Sliding wear tests were conducted with the use of a nano-tribo tester, i.e., ball-on-disc apparatus. Results demonstrate that the cavitation erosion mechanism of the TiAlN and AlTiN coatings rely on embrittlement, which can be attributed to fatigue processes causing film rupture and internal decohesion in flake spallation, and thus leading to coating detachment and substrate exposition. At moderate loads, the sliding wear of thin films takes the form of grooving, micro-scratching, micro-ploughing and smearing of the columnar grain top hills. Compared to the SS reference sample, the PVD films exhibit superior resistance to sliding wear and cavitation erosion.

Highlights

Stainless steel grade AISI 304 (SS) is one of the most widely used modern structural materials due to its high corrosion resistance, satisfactory mechanical properties, sufficient weldability and good formidability [1,2,3,4,5,6]
Stainless steel is used for manufacturing different components and considered to be a structural metal with moderate resistance to cavitation erosion
The application of physical vapor deposited (PVD) coatings is proposed as a promising solution, easy to implement in industrial practice, for preventing the wear of stainless steel parts

Summary

Introduction

Stainless steel grade AISI 304 (SS) is one of the most widely used modern structural materials due to its high corrosion resistance, satisfactory mechanical properties, sufficient weldability and good formidability [1,2,3,4,5,6]. The wear resistance of SS can be improved by depositing different systems of hard coatings, such as TiN, CrN, TiAlN, AlTiN or AlCrN, or even by depositing stainless steel coatings enriched with silver [3,7,8,9,10]. Modern types of TiAlN or AlTiN hard films are widely used for manufacturing machining tools or machine components to reduce their tribochemical and adhesive wear, or to make them resistant to severe thermal conditions. The use of AlTiN and TiAlN coatings (with different ratios of Al/(Ti + Al)) can be an effective way of increasing the wear resistance of stainless steel components exposed to severe wear processes [9,10,11,12,13,14,15].

Objectives

Methods

Results

Conclusion