Dependence of Wear and Mechanical Behavior of Nitrocarburized/CrN/DLC Layer on Film Thickness

Abstract

Diamond-like carbon (DLC) films are amorphous metastable carbon form that provide interesting mechanical and tribological properties. The role of film thickness influence upon wear and mechanical properties is of interest and not yet fully reported. In this study, two samples of previously plasma nitrocarburized, quenched and tempered H13 steel were duplex treated. First, a physical vapor deposition (PVD) chromium nitride (CrN) layer was applied, followed by a top final diamond-like carbon layer applied by plasma-enhanced chemical vapor deposition (PECVD). To evaluate thicknesses influence on mechanical and wear properties of coatings, samples were treated using two different thicknesses of both layers. In this study, the thickest CrN and DLC case presented higher hardness and better tribological properties, however, its failure occurs in brittle fashion.

Study on the Tribological Behavior of Wear and Friction Coefficient on AISI M35 High-Speed Steel with and without DLC Coating

“…A 71% reduction was obtained on the DLC-coated surface (k = 5.27E-14±6.55E-15 m 3 /N.m) in relation to the AISI M35 substrate (k = 1.83E-13±3.25E-14 m 3 /N.m). The graphical analysis reinforces the previous discussion about wear caps, showing that the coating application can provide improvements in tribological properties, in this case, resistance to abrasive wear 1,21,65 . also mentioned expressive differences in wear reduction when applying the DLC.…”

“…The edges are not homogeneous, which may be related to the sphere instability during sliding. The opposite is observed in the craters generated on the uncoated surface, where the edges were more homogeneous 1 . investigated the influence of DLC deposited on AISI H13 steel during the microabrasive test.…”

“…The micro-abrasive wear test was performed according to the guidelines of ENV 1071 (EUROPEAN COMMITTEE FOR STANDARDIZATION, 2001). The equipment used was the Compact Calo tester CATc Anton Paar equipment, 25 mm diameter AISI 52100 steel ball frequently used in other studies 1,22,35 . A silicon carbide abrasive solution (SiC -99.98%) diluted 20% in ethylene glycol was used according to 36 , who mentions that it is a recommended choice due to the positive results obtained in other studies.…”

“…Diamond-Like Carbon (DLC) refers to allotropic forms of carbon that are metastable 1 and have an amorphous structure consisting of carbon-carbon bonds in sp 2 configuration (graphite) and carbon-carbon bonds in sp 3 configuration (diamond) 2 . Hydrogen can also be incorporated into the chemical composition along with the sp 3 configuration, which will classify the DLC as hydrogenated or non-hydrogenated according to a percentage content.…”

“…The "adhesion" theme is frequently discussed regarding the application of DLC, since its behavior in elastic phase differs from the behavior of the substrate. This difference in behavior can be explained by the difference in the material Young's modulus 1,13 . To reduce the intrinsic disadvantages of amorphous carbon films, studies are carried out to investigate the addition of elements (doping and/ or interface layer) such as titanium, chromium, tungsten, nitrogen, silicon, among others 2,18 evaluated the applicability of DLC a-C: H as a coating for cutting tools in the dry turning process of hardened AISI 52100 steel.…”