Abstract
SPS-fabricated zirconia(3Y)/SUS410L FGM consisting of seven layers was characterized by microfocusing XRD and Raman scattering methods. The formation of monoclinic zirconia phase was verified in the interlayers with lower contents of zirconia(3Y) than 70vol% and the largest amount of monoclinic zirconia was detected in the third interlayer with 60vol% zirconia(3Y). From the Raman peak shift of tetragonal zirconia, the existence of fairly high compressive stress was detected in the interlayers with the zirconia(3Y) of 60vol% and 70vol%, resulting in the formation of monoclinic zirconia. While tensile stress was observed in the interlayes with the content of more than 80vol% zirconia(3Y). Further, the increase of the lattice constant of 410L steel(Fe-Cr alloy) indicates that tensile stress is applied on the 410L steel region in all interlayers. Mechanical instability in the outer interlayers with more than 80vol% zirconia(3Y) is suggested from the drastic change of internal stress mode from compressive to tensile in the region of 70vol%-80vol% zirconia(3Y).
