Evaluation of adhesion strength of sol-gel ceramic insulation for HTS magnets

Adhesion strength of high temperature insulation materials deposited on silver was investigated. CeO/sub 2/ and ZrO/sub 2/ based coatings on Ag substrates were prepared by the sol-gel technique. Experiments for determining the adhesion strength between insulations and silver were performed using a mini tensile testing machine. The microstructures of coatings and their interfaces were determined by means of SEM, EDS, and X-ray diffraction. The results indicated that the failure was in the form of a mixed type as interfacial/cohesive defect. The average adhesive strength of ZrO/sub 2/, CeO/sub 2/, ZrO/sub 2/+20 wt%MgO, Zr/sub O/2+8 wt%Y/sub 2/O/sub 3/, ZrO/sub 2/+8 wt%CeO/sub 2/, ZrO/sub 2/+15 wt%In/sub 2/O/sub 3/ and ZrO/sub 2/+15 wt%SnO/sub 2/ were found to be 0.763, 0.913, 1.045, 1.150, 0.915 0.833 and 0.797 MPa, respectively. Y/sub 2/O/sub 3/, MgO, and CeO/sub 2/ doped ZrO/sub 2/ showed the best adhesive properties.