Elastic Modulus Measurements in Plasma Sprayed Deposits
Jay S. Wallace, J Ilavsky
A technique has been developed to characterize the elastic modulus of zirconium oxide-8% yttrium oxide plasma sprayed deposits. A commercial hardness indenter has been modified to record load-displacement as a spherical ball is elastically loaded onto the surface of the material to be measured. The resulting data are used to calculate the elastic modulus. Since the loads used are in the elastic region, the technique is, in theory, nondestructive. Relatively small areas of the material, approximately 50 (micro)m in diameter, are sampled by the indenter, allowing local mapping of elastic modulus variations throughout the deposit. Using this technique, elastic modulus variations have been measured through the thickness of the deposit. Also, different moduli were measured in the cross-section and through the thickness and these differences are correlated with the microstructure. Finally significant increases in elastic modulus have been found in samples annealed for 2.5 h at 1100 [degrees] C. These changes have been correlated with small angle neutron scattering measurements of void surface area.