Grain boundary disordering in binary alloys

This letter reports a grain boundary (GB) premelting/prewetting model based on the Miedema model and computational thermodynamics, predicting that GB disordering can start at as low as 60%–85% of the bulk solidus temperatures in selected systems. This model quantitatively explains the long-standing mystery of subsolidus activated sintering in W–Pd, W–Ni, W–Co, W–Fe and W–Cu, and it has broad applications for understanding GB-controlled transport kinetics and physical properties. Furthermore, this study demonstrates the necessity of developing GB “phase” diagrams as a tool for material design.