Advanced Materials Research Group

Seminar: Substrate Effect on the Residual Stress of Suspension HVOF Sprayed YSZ Coatings by Tunji Owoseni

 
Location
ESLC B12
Date(s)
Wednesday 7th November 2018 (14:00-14:45)
Contact

For more information on this presentation, please contact Tunji Owoseni.

For more information on the AMRG Seminar Series, or if you would like to arrange to give a presentation, please contact Hayley Revill.

Description

The Advanced Materials Research Group (AMRG) would like to welcome you to attend the following seminar:

Substrate Effect on the Residual Stress of Suspension HVOF Sprayed YSZ Coatings

By Tunji Owoseni

Abstract:

Thermally sprayed coatings have residual stresses due to the processing techniques where the particles go through thermal softening / melting, high velocity impact and rapid solidification. The nature and magnitude of the residual stresses in these coatings determine the coating/substrate bond strength and failure mechanisms. This investigation work presents a non-destructive neutron diffraction residual stress evaluation of suspension high-velocity oxy-fuel (S-HVOF) thermal sprayed YSZ coatings onto 304 stainless steel substrates and CoNiCrAlY bond coat. S-HVOF spray is a high deposition efficiency process to deposit coatings from sub-micron or nanometric feedstock particles. Neutron diffraction measurements were performed at the UK ISIS facility, using ENGIN-X pulsed neutron diffractometer to obtain through thickness residual stress profiles. The Z-scanning method was used to avoid pseudo-strains in the neutron diffraction measurements near the coating surface whereby the incident neutron beam/gauge volume was partially submerged and traversed vertically out of the horizontal coating surface. The elastic modulus of the coatings were also measured by depth sensing indentation on the coatings cross sections. The residual stress changed from tensile to compressive in the YSZ coatings on SS 304 while it remained entirely compressive in the YSZ on CoNiCrAlY bond coat. 

Advanced Materials Research Group

Faculty of Engineering
The University of Nottingham
University Park
Nottingham, NG7 2RD



email:AdvMaterials@nottingham.ac.uk