X-ray diffraction study on inelastic deformation behavior of Ni-base single crystal superalloy

Damage assessment method of gas turbine hot-gas-path components such as blade and nozzle was required to evaluate remaining life of these components; especially, the method for estimating whether inelastic deformation occurred or not is important for structural integrity assessment. In this study, in order to provide the way for evaluating the plastic deformation of gas turbine hot-gas- path components, X-ray diffraction experiments were performed for tensile deformed Ni-base single crystal superalloys using synchrotron radiation at SPring-8, and the relations between applied tensile strain and X-ray diffraction data were studied. The width of to-rocking curve which represents the deviation of crystal orientation increased with the increase of applied tensile strain. This means that plastic deformation cause the crystal rotation. X-ray diffraction peak width increased with the increase of applied tensile strain. Williamson-Hall analysis was applied to calculate micro-strain. Micro-strain showed drastic increase in the early stage of tensile tests. It suggests that the measurement of micro-strain by X-ray diffraction is useful for estimating whether plastic deformation occurred or not in actual gas turbine blades. Copyright (C) 2016 The Authors. Published by Elsevier B.V