This project combines the theme above – carbon addition to overcome carbon loss during spraying, as well as strengthening of the metallic matrix, either through SiC whisker reinforcement or Si solid solution strengthening.
SiC whiskers (at two concentrations) will be added to two different carbide composite powders (Cr3C2-NiCr and WC-NiCr) and sprayed using HVOF and plasma spraying. The resulting coatings will be characterised in detail to assess the concentration of entrained Si, and in what form the Si si retained in (SiC or dissolved Si in the metallic binder). 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 SiC addition was successful in being able to develop the desired phase composition in the coating and improve the Ni mechanical properties.
Undergraduate
None
No lab has been assigned to this project