Optimization Of Multi-Module CrN/CrCN Coatings

Abstract

In the paper was proposed optimization procedure supporting the prototyping of the geometry of multi-module CrN /CrCN coatings, deposited on substrates from 42CrMo4 steel, in respect of mechanical properties. Adopted decision criteria were the functions of the state of internal stress and strain in the coating and substrate, caused by external mechanical loads. Using developed optimization procedure the set of optimal solutions (Pareto-optimal solutions) of coatings geometry parameters, due to the adopted decision criteria was obtained. For the purposes of analysis of obtained Pareto-optimal solutions, their mutual distance in the space of criteria and decision variables were calculated, which allowed to group solutions in the classes. Also analyzed the number of direct neighbors of Pareto-optimal solutions for the purposes of assessing the stability of solutions.Keywords: multi-module coatings, optimization, Pareto sets, internal stress W pracy została zaproponowana procedura optymalizacyjna wspomagająca dobór geometrii wielomodułowych powłok CrN/CrCN, osadzonych na podłożu ze stali 42CrMo4, pod kątem właściwości mechanicznych. Przyjęte kryteria decyzyjne były funkcjami stanu naprężeń oraz odkształceń wewnętrznych w powłoce i podłożu, powstałych na skutek mechanicznych obciążeń zewnętrznych. Wykorzystując opracowaną procedurę uzyskano zbiór optymalnych wartości parametrów geometrii powłok (rozwiązania Pareto-optymalne), ze względu na przyjęte kryteria decyzyjne. Do celów analizy otrzymanych rozwiązań określono ich wzajemne odległości w przestrzeni kryteriów i zmiennych decyzyjnych, co umożliwiło pogrupowanie rozwiązań w klasy. Analizowano również liczbę bezpośrednich sąsiadów rozwiązań Pareto-optymalnych w celach oceny stabilności rozwiązań.

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

“…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). In order to limit these effects, for example, a more complex structure of the coating is used such as multilayer coatings and multi-module Cr/CrN (Marulanda et al, 2012;Polcar et al, 2009;Ratajski et al, 2015), CrN/CrCN (Gilewicz et al, 2015;Szparaga et al, 2015aSzparaga et al, , 2015b or gradient CrN/Cr(C)N coatings (Fuentesa et al, 2008;Ratajski and Szparaga, 2012;Szparaga et al, 2015c;Zhang et al, 2009). The such structure of coating increases the resistance to cracking and enhances the adhesion state, e.g., by reducing residual stresses in the coating.…”

“…For nearly three decades in designing of structure of multi-layer, monolayer and multi-module coatings a great role play finite element method (FEM) simulations (Dobrzański et al, 2007;Pakuła et al, 2016;Ratajski and Szparaga, 2012;Szparaga et al, 2015aSzparaga et al, , 2015cŚliwa et al, 2016;Śliwa, 2017;Zukowska et al, 2016). Among other FEM model was used in optimisation procedure for eight-layer Cr/CrN coating on A2 steel substrate in terms of mechanical properties (Lakkaraju et al, 2006).…”

“…The result of the simulation was optimal architecture consisting of Cr/CrN modules of different thicknesses, i.e., the thinnest possible metallic Cr layer at substrate/coating interface and thickest CrN outer layer. In our research (Szparaga et al, 2015a), we have developed the optimisation procedure supporting the prototyping of the geometry of multi-module CrN/CrCN coatings, deposited on 42CrMo4 steel substrates, in terms of mechanical properties. Decisional criteria were the functions of the state of residual stress and strain in the coating/substrate system, generated by external mechanical loads.…”

Computer Simulation of the Relationship between Selected Properties of PVD Coatings

“…Finite elements method is at present one of most widely used practical methods of solving of various engineering problems and it permits on time shortening of projecting and gives possibility to research the influence of each factors in the mathematical model [1][2][3][4][5][6]. Usage of this method from economic point of view is well-founded because more than once it permits to avoid expensive laboratory investigations, and results obtained during simulation are reliable and approximate to real values [7][8][9][10].…”

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.…”