Fracture toughness and sliding properties of magnetron sputtered CrBC and CrBCN coatings

Abstract

CrBC and CrBCN coatings with low and high B contents were deposited on 316L steel and Si wafers using an unbalanced magnetron sputtering system. Mechanical properties including hardness (H), elastic modulus (E) and fracture toughness (K Ic) as well as residual stresses (σ) were quantified. A clear correlation between structural, mechanical and tribological properties of coatings was found. In particular, structural analyses indicated that N incorporation in CrBC coatings with high B content caused a significant structural evolution of the nanocomposite structure (crystalline grains embedded into an amorphous matrix) from nc-CrB 2 /(a-CrB x , a-BC x) to nc-CrN/(a-BC x , a-BN). As a result, the hardness of CrBC coating with high B content decreased from 23.4 to 16.3 GPa but the fracture toughness was enhanced. Consequently, less cracks initiated on CrBCN coatings during tribological tests, which combined with the shielding effect of a-BN on wear debris, led to a low friction coefficient and wear rate.

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

“…However, the coating B, in which the largest share is hard layers (CrN), is characterised by the smallest value of this parameter, coating of B type is also characterised by the largest H/E, H 3 /E 2 ratios and value of W e (elastic recovery) indicator. The higher value of these indicators means higher resistance to a fracture toughness and higher resistance to plastic deformation of the coating (Leyland and Matthews, 2000;Musil et al, 2012aMusil et al, , 2012bWang et al, 2015Wang et al, , 2016Wang et al, , 2017aWang et al, , 2017bWang et al, , 2018, what may indicate a greater ability of the coating to carry higher mechanical loads. In turn, coating A is characterised by the lowest values of these indicators, i.e., according to the above interpretation, this coating has the highest susceptibility to plastic deformation.…”

Study on Microstructure and Tribological Mechanism of Mo Incorporated (AlCrTiZr)N High-Entropy Ceramics Coatings Prepared by Magnetron Sputtering

“…Banerjee et al found that the coating with medium hardness showed the best wear resistance, while the coating with the highest hardness showed brittle characteristics [11]. Wang et al found that the CrBCN-L coating with the lowest hardness (17.9 GPa) but the best toughness (K IC = 2.81 MPa m 1/2 ) showed the best wear resistance (wear rate = 2.4 × 10 −7 mm 3 /(N•m)) [12]. Therefore, overcoming the tradeoff between the fracture toughness and hardness of materials has become an effective way of enhancing the wear resistance of materials.…”

Effect of graphene on the microstructure, mechanical properties, and wear behavior of plasma‐sprayed Al2O3–Cr2O3 coating

“…The ceramic coatings, including Al 2 O 3 -based coatings, have broad application prospect in sliding and rolling bearings because of their excellent wear resistance. 18,19 The low coefficient of friction (COF) cannot only extend service life of bearings but also save energy. So, how to reduce the COF of ceramic coating materials with improved wear resistance is always an important topic.…”