Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
Effect of pre-placed powders of graphene and graphite on dilution and hardness of Stellite 6 coatings processed by PTA
Submission Author:
João Felipe Sippel , PR
Co-Authors:
João Felipe Sippel, Willian Oliveira , Juliane Ribeiro da Cruz Alves, Ana Sofia D'Oliveira
Presenter: João Felipe Sippel
doi://10.26678/ABCM.COBEM2023.COB2023-1900
Abstract
The tailoring of coatings by changing the chemical composition with graphite and graphene has demonstrated potential to improve mechanical and abrasive resistance by combining self-lubricating properties with superior strength. Among the alloys used for abrasive wear resistance applications Stellite 6 a CoCrWC-based alloy, is an industrial reference in applications where high resistance to wear, cavitation and high temperatures are required. Tailoring of coatings with additions of graphite and graphene have been carried out using techniques such as thermal spraying and thin films depositions. However, Stellite 6 hardfacing coatings modified by graphite and graphene 6 have not yet been. This work is part of an on going project on tailoring Stellite 6 coatings processed by Plasma Transferred Arc for wear resistance applications. Particularly it addresses the addition of graphite and graphene to the Co-based alloy, as powder mixtures and as pre-placed powders. The pre-placed layers on the 304 stainless steel substrate was done on three different surface finishing: as cold-rolled, ground with #36 sandpaper and ground with # 220 sand paper. The objective is to investigate the influence of the surface roughness on anchoring and retention of these carbon-based particles, as well as its impact in bead characteristics and Vickers microhardness. Vickers microhardness profiles was determined for each coating. Experimental procedures showed that mixture of powders is not effective procedure to achieve the modification of Stellite 6 coatings with neither graphite nor graphene. Results revealed that graphite modified coatings induced an increase in hardness whereas graphene modified coatings exhibit a behavior in hardness that depends on surface finishing. Dilution was increased with the addition of both powders reveling an interaction between powders, substrate and plasma arc.
Keywords
Plasma Transferred Arc, stellite 6, graphene, graphite, Cobalt alloys
