Comparison of Traditional and Cold Spray Fabricated Ring and Plug Standards for Neutron Diffraction

Accurate residual stress measurement is essential for validating structural integrity, but reliability depends heavily on the microstructural consistency of the standards used. This work presents a modern assessment of Versailles Project on Advanced Materials and Standards (VAMAS) ring and plug samples. Using the HIDRA diffractometer at the High Flux Isotope Reactor, high-resolution measurements of traditional VAMAS standards were compared with a new generation of standards fabricated via cold spray additive manufacturing. The results demonstrate that sample quality is a critical factor in measurement reproducibility. Key considerations include the relationship between grain size, texture, and the sampling gauge volume. While traditional rolled plate standards exhibit systematic variations in texture that can adversely affect strain determination, the cold spray builds show a unique, low-magnitude residual stress profile with minimal geometrical dependency. This work presents residual stress mapping and texture data to illustrate these effects. These findings support the development of a new set of VAMAS standards produced via cold spray to improve calibration and inter-laboratory reliability for neutron residual stress mapping.