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. (C) 2008 American Institute of Physics.