On grain boundary segregation in molybdenum materials

K. Leitner (née Babinsky), P.J. Felfer, D. Holec, J.M. Cairney, W. Knabl, A. Lorich, H. Clemens, S. Primig
Materials & Design 135 (2017) 204-212.

This is a comprehensive crystallographic and chemical study of grain boundary segregation in molybdenum materials by atom probe crystallography and correlative techniques. These technological important materials are used in high temperature, electronics and coating technologies, but their application is often limited by intergranular failure due to grain boundary decoration with solutes, especially in the recrystallized state.

Here we present the first thorough overview of segregation at >20 high-angle grain boundaries (GBs) in molybdenum materials in their as-deformed and recrystallized states. This shows the detrimental elements P, N, and O at all random high angle GBs, whereas C, which has a strengthening effect, is only found at low-Σ GBs in recrystallized materials. We support our experimental observations by first principle calculations.

This opens a pathway towards the design of molybdenum products for future structural applications.