Analysis of the effect of antiwear CrN coating thickness on the evolution of thermomechanical interactions in the substrate/PVD coating system

Abstract

The main goal of this study was to analyze the application possibilities of modulated temperature thermomechanical analysis (MT TMA) for the evaluation of thermomechanical interactions in substrate/PVD coating systems on the example of examination of influence of changes in thickness of a coating on internal stress evolution in these systems. As an indicator of the stress state in the coating at a given measurement temperature, the changes in a value of the equivalent thermal expansion coefficient of the system a AC , which is calculated based on registered changes in temperature and elongation of the sample, were assumed. Independently, numerical simulations of the residual thermal stresses were carried out using finite element method. The objects of research were systems composed of substrates of HS6-5-2 steel and a single layer of chromium nitride CrN with thickness 2, 4, 8 and 10 lm, deposited on the substrate by cathodic arc evaporation method. In order to determine the effect of the CrN coating thickness on evolution of thermomechanical interactions in the system, the samples were annealed according to the assumed curve comprising nine-step isothermal annealing in the range of 150-500°C. Obtained results have shown that MT TMA is useful to study the thermomechanical interactions in substrate/PVD coating systems. In particularly, obtained values of a AC , calculated on the basis of measured elongation changes for substrate/ PVD coating systems, are lower than for the substrate without coatings, and they increase with the thickness of the deposited coating. This means that there is a decrease in compressive stresses in the coatings with increasing coating thickness. It was also found that with increasing temperature there is a local maximum value of a AC , which indicates the temperature of deposition of the coating. This is a key parameter from a technological point of view of the PVD processes.

Mechanical and anti-wear properties of multi-module Cr/CrN coatings

“…Particular interest in this area is directed towards the coating on the base of chromium nitride. These coatings are, among other, characterised by relatively low value of residual stress and good resistance to oxidation at high temperatures (Gauzzi et al, 2008;Lee et al, 2001;Mydłowska et al, 2016). For monolayer coatings deposited by PVD techniques, it is often observed that increasing the hardness of the coatings is accompanied by a simultaneous increase in the Young's modulus and decrease of their ductility (impact resistance), which leads to a reduction of coating's fracture toughness due to the reduction of their ability to dissipate mechanical energy (through plastic deformation).…”

Targeting a channel coating by using magnetic field and magnetic nanofluids

“…Coatings play an important role in many technological areas including thermal industries, manufacturing of gas turbine engines widely used in aerospace industry, industrial power generations, color sciences, insulation industries, solar cells, and marine applications. Providing a proper coating can enhance the performance and useful life of the system [1][2][3]. Moreover, most of metals are working under varying harsh conditions and environments.…”

Numerical Analysis of Strength Properties of Anatomical General Surgical Tweezers

“…Keywords:, Computational materials science; Finite Element Method, Stress, Strain, Deformation, Anatomical surgical tweezers A contemporary technological development makes it necessary to look for new constructional solutions that aim at the improvement of the effectiveness and quality of a product, at the minimization of dimension and mass as well as the increasing of reliability and dimension stability in the operation conditions [1][2][3][4][5][6]. Tweezers are classified as picking tools consisting of two arms produced in a plastic working process and connected permanently by welding.…”