Mechanical Properties of High RRR Niobium With Different Texture

High purity bulk niobium RRR ~ 300 is the standard material used for SRF cavities since this has been the most promising material for over 10 years. Mechanical properties of the high RRR niobium play a critical role in the physical integrity of these structures. It is well known that the mechanical properties of polycrystalline high RRR niobium are affected by a variety of possible contributors: crystallographic texture, grain size, and impurity concentration. Tensile tests were carried out using three groups of niobium samples from MSU SRF cavity and Fermi International Linear Collider projects with different texture and grain size, which came from two different manufacturers. For some of the groups the tensile tests were done with different orientations with respect to the sheet. Orientation Imaging Microscopy (OIM) data were collected in these samples. The relationships between mechanical properties, texture, and grain size in these samples are analyzed.