Investigation of multicomponent nanolayer coatings based on nitrides of Cr, Mo, Zr, Nb, and Al

Development of a Model of Crack Propagation in Multilayer Hard Coatings under Conditions of Stochastic Force Impact

“…On the qualitative level, the proposed model can be confirmed by the observation of the crack formation process in multilayer and nanolayer coatings during the action of stochastic loading. In particular, the cutting process is one of such processes [ 59 ]. Under the influence of loads (cutting forces) that arise during the process of cutting, microcracks are formed in the coating structure.…”

“…Let us consider the influence of the nanolayer coating structure on the pattern cracking using the example of the Zr,Nb-(Zr,Nb)N-(Zr,Nb,Al)N coating ( Figure 6 ). In this coating, the nanolayers are characterized by a balanced combination of considerable hardness and ductility [ 57 , 58 , 59 ]. Figure 6 exhibits the structure of the coating that was deposited on a carbide substrate after the turning of steel.…”

“…In particular, as a possible direction for the further development of this model, the factors with a significant influence on crack formation in a multilayer coating can be considered, as follows: the layer interface is gradient, which is, the transition from one layer to another occurs smoothly with a gradual increase in the percentage composition of some elements and a decrease in others [ 21 , 35 , 36 ]; a three-dimensional model more accurately reflects the specific features of the process, although it requires much more computational capabilities; the temperature factor affects both the mechanical properties of the layer materials and the state of the layer interfaces (in particular, due to the difference in the coefficients of thermal expansion of conjugate layers); and, internal and residual stresses (depending, in particular, on the total coating thickness and the thicknesses of nanolayers [ 59 ]) have a noticeable influence on the crack formation. …”

“…According to a number of papers [ 2 , 3 , 21 , 35 , 36 , 51 , 52 , 53 ], due to nanolayer structure, the coating demonstrates high hardness at elevated temperatures and high oxidation resistance. It was assumed that the coating had a three-layer structure [ 35 , 38 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 ].…”

Investigation of the Influence of Microdroplets on the Coatings Nanolayer Structure

“…In particular, the study focused on the properties of the (Ti,Al,Zr)N coating has found the presence of a multiphase structure with a dominant phase based on fcc-TiN with dissolved Al and Zr, but phases of Zr 3 A1N, Ti 3 A1N, and A1N have also been detected [56,57]. The coating of (Ti,Al,Mo)N has also been studied in [58][59][60][61][62] [60]. Meanwhile, the current study is focused on microdroplets embedded into the structure of the coatings under consideration.…”