Recent development of instrumentation for high resolution energy resolved neutron imaging enables non-destructive studies of relatively thick materials produced by additive manufacturing. Microstructure within several centimeter thick samples can be measured with spatial resolution of ~100-200 µm over area as large as ~10 cm^2 in one experiment. This technique is based on the analysis of neutron transmission spectra measured simultaneously for each pixel of the resulting data set.
In this paper we demonstrate the possibility to image distribution of some bulk microstructure properties, such as residual strain, texture, voids and impurities in various Inconel 625 samples produced with direct metal laser melting (DMLM) method. The measurement results provide a possibility to correlate the processing parameters of additive manufacturing to resulting microstructure. The results can also be very helpful for the validation of finite element models which many industries use to predict the residual stress distributions in additive manufactured components.