Effects of Different Plasma Nitrided Layers on the Tribological Performance of DLC Coatings

Pedro Henrique Teshima Shioga,Aloisio Nelmo Klein,Jose Daniel Biasoli De Mello,Gisele Hammes,Cristiano Binder

doi:10.1590/1980-5373-mr-2015-0455

Pedro Henrique Teshima Shioga, Aloisio Nelmo Klein + Show 3 more

Open Access

https://doi.org/10.1590/1980-5373-mr-2015-0455

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Journal: Materials Research	Publication Date: Sep 12, 2016
Citations: 18	License type: cc-by

Affiliation: Universidade Federal de Santa Catarina

Abstract

When multifunctional surface engineering processes that combine purpose-oriented phases are applied to soft substrates, a combination of high wear resistance, high load support and low coefficients of friction can be achieved. In this study, the effects of different nitrided layers on the tribological behaviour of a diamond-like carbon (DLC) film deposited on a SAE 1040 steel were investigated. The nitriding was carried out under different temperatures and gas mixtures to create three distinct nitrided layers: two compound layers with predominant e and γ' phases and a diffusion layer. All of the surfaces were then coated with DLC deposited via plasma-enhanced chemical vapour deposition (PECVD). The tribological tests indicated that the best performance was achieved for a specific combination of hardness, surface roughness and nitride type. The best load-bearing capacity between the DLC coating and the soft substrate was achieved when the nitrided layer was primarily a diffusion layer.

Highlights

Diamond-like carbon (DLC) encompasses a family of coatings with widespread use in tribological applications due to their low coefficients of friction in metal-DLC pairs[1,2,3], which are associated with extremely low wear rates (10-9-10-10 mm3/Nm)[3,4].Hard solid lubricant coatings have found success in many applications, those involving pure elements such as silicon and advanced materials[5,6,7,8]
This nitrided layer structure is achieved by accelerating nitrogen ions against the sample surface, cleaning the surface, heating the workpiece, and providing active nitrogen that diffuses into the matrix[20,21]
The tribological behaviour of the multipurpose coatings (DLC+nitrided layer) was evaluated through a durability test using the method presented by de Mello and Binder[30] In this method, the sample surface is subjected to reciprocating movement under an increasing normal load until failure and with a consequent increase in friction

Summary

Introduction

Diamond-like carbon (DLC) encompasses a family of coatings with widespread use in tribological applications due to their low coefficients of friction in metal-DLC pairs (usually 0.1

Materials and methods

Results and Discussion

Conclusions