Abstract:
The present thesis approaches an important domain of Materials
Science and Engineering namely that of thermally sprayed WC and CrC
cermet based coatings with high density, good adhesion to the
substrate, reduced porosity and also a relatively reduced decarburisation
level due to modern HVOF and HVAF thermal spraying techniques. This
type of coatings have a wide range of application, especially in the past
decade, in various industrial fields like aeronautics, automotive, petrochemical,
cellulose, energetics, chemical industry, etc. The deposited
coatings aim to increase the lifetime of various components subjected to
severe working conditions and also to recondition worn parts.
This work presents research studies conducted on cermet
coatings like WC-10Co-4Cr, Cr3C2-25NiCr, Cr3C2-37WC-18M and WCFeCrAl
in order to obtain protective coatings deposited using the HVAF
spraying process comparable in terms of microstructure, wear and
corrosion resistance with coatings deposited using the HVOF spraying
process but having as advantage a relativelly lower manufacturing cost
due to the use of air as combustion gas.
