Ni-base superalloys have long been used in high temperature applications, including the high-demand environments of the high pressure turbines in jet engines. The remarkable properties of these alloys are the result of precipitation strengthening, frequently by Ni3Al. The Ni3Al precipitates are however prone to coarsening, leading to a degradation of properties over time. The ability to retard this coarsening would prove highly useful in the development of these alloys, and this may be provided by the use of alloys which also contain Ni3V precipitates. Ni3V precipitates can form with various morphologies, and it is important to examine the development of these precipitates and the dependence on their lattice parameters. The structure of the Ni3V phase is best studied by neutron diffraction, and so a request is made for two days on the Polaris instrument.