High resolution imaging and analysis of residual elastic strain in an additively manufactured turbine blade

Abstract

Using recently developed microchannel plate (MCP) neutron area detectors at a pulsed neutron source provides a method of fast non-destructive imaging and characterisation of advanced materials at unprecedented spatial resolution. The energy resolved neutron transmission spectrum can be found from the neutron time of flight (ToF), this provides valuable information about the crystallographic structure within the sample such as the average residual elastic strain in the incident beam direction. By measuring this spectrum at a number of sample orientations information is built up about the strain distribution throughout the specimen. The energy-resolved neutron transmission spectrum of an additively manufactured turbine blade was measured at the Engin-X instrument, ISIS, UK. A high resolution three-dimensional reconstruction of the neutron attenuation coefficient of the blade was recovered, then analysis of the energy resolved spectrum gave insight into the underlying residual elastic strain profile imparted by the advanced manufacturing process.