Zêta Hydride Precipitation in Zirconium Alloys: an Example of Elastically Driven Morphology of Coherent Trigonal Precipitates inside a Сlose-Packed Hexagonal Matrix

摘要: The influence of a crystallographic symmetry break on the morphology precipitates during coherent precipitation trigonal phase in close packed hexagonal matrix is analyzed. It pointed out that spite isotropy stress free strain precipitate basal plane, existence an extra elastic constant (associated to loss symmetry) induces morphological evolution from shape having revolution around threefold axis needle-like one oriented along compact directions plane. These general considerations are applied case zeta zirconium hydrides crystallography which has been recently identified be with alpha Zr matrix. and heterogeneity numerically addressed by using different approaches. An analytical approximation energy based Eshelby equivalent inclusion method allows obtaining qualitative criterion determine occurrence bifurcation hydrides.