AZIMUTHAL DEFORMATION PARTICULARS OF SINGLE-CRYSTAL CLADDING OF HIGH-TEMPERATURE FUEL ELEMENTS

摘要

The particulars of the azimuthal deformation and the reasons for the formation of faceting on single-crystal molybdenum cladding with the <111> axis oriented longitudinally in tests for structural creep at 1650℃ under internal argon gas pressure are investigated. It is shown that the periodic local nonuniformity of the azimuthal deformation of <111> cladding and the appearance of faceting are associated with the difference of the maximum shear stress in the active slip planes for single crystals with a bcc lattice in the range of orientations of the stretch axis <110>-<112>. Cladding sections located at the center of the interval <110>-<112> possess weak resistance to high-temperature creep and sites of deformation localization.