TWI Industrial Member Report Summary 588/1997
By A J Sturgeon
High velocity oxyfuel (HVOF) spraying is increasingly considered as an alternative thermal spraying process to air plasma and detonation flame spraying for the preparation of high quality coatings of tungsten carbide-cobalt (WC-Co). Such coatings provide protection against severe wear such as abrasion, adhesion, fretting and particle erosion for a wide range of industrial applications. The achievement of good wear protection is highly
dependent on the deposition of a coating having the correct microstructure. There is very little published information on the microstructure of HVOF sprayed WC-Co coatings ahd on how this influences wear performance. This work has sought to characterise the microstructure of two WC-Co coatings with very different abrasive wear rates. Characterisation of the coating microstructure was undertaken using scanning electron microscopy, x-ray diffraction and chemical etching techniques.
To characterise the microstructure of WC-Co coatings prepared using the HVOF process.
To determine the microstructure necessary to give best resistance to abrasive wear.