中科院固体物理研究所知识库

The tetragonal to monoclinic martensitic transformation of plasma-sprayed 3 mol % Y2O3-ZrO2 coatings is investigated by electron backscatter diffraction. The original metastable tetragonal phase shows an approximate "basal" texture with {001}(t) parallel to the coating surface. Based on the orientation analysis, plenty of monoclinic variants with atypical correspondence which indicates the c(t) axis transforms to the am axis where (100)(m)//(001)(t), (010)(m), and (001)(m)//{110}(t) are clearly identified in addition to the correspondence where the c(t) axis transforms to the c(m) axis. Moreover, three growth modes are proposed and discussed according to strain accommodation. The observed sequential growth obeys the correspondence of the c(t) axis to the c(m) axis. Fourfold growth combines the correspondences of the c(t) axis to the c(m) and a(m) axes. The interleaving growth follows the correspondences of the c(t) axis to the c(m) axis within three tetragonal domains. These phenomena demonstrate the typical twin-related and self-accommodating configuration, which is in agreement with the phenomenological theory. These finding provide fundamental insight into the martensitic transformation mechanism and demonstrate a route for increasing the lifetime by controlling the tetragonal to monoclinic phase transformation.