Metallic Ni is the most commonly used metallic binder for carbide composites other than WC. The fcc structure of Ni offers high ductility to the metallic binder, but poor mechanical strength and wear resistance. In order to improve the wear resistance of the Ni binder, this work will aim to add metallic tungsten to the Ni+carbide composite powders prior to thermal spraying by HVOF and plasma spraying. One student will study the Cr3C2-NiCr + W system, while the other student in the pair will study the TiCN-Ni+W system. A “low” and “high” concentration of W will be added to preformed carbide composite powders. The resulting coatings will be characterised in detail to assess the concentration of entrained tungsten.
Coatings will be analysed by combined DSC and TGA to determine the energy changes that occur due to compositional developments with heat treatment. Heat treatment trials below and above each characteristic DSC peak will enable ethe change in composition to be determined through XRD/EDS and SEM analysis. Longterm heat treatment (125 hours) at 900°C will enable the coating compositions to reach equilibrium and determine if the concept of W addition was successful in being able to develop the desired phase composition in the coating.
Undergraduate
None
No lab has been assigned to this project