SOLID-SOLUTION STRENGTHENING IN TERNARY B2 IRON ALUMINIDES CONTAINING3D TRANSITION-ELEMENTS

The room temperature yield strengths of extruded ternary iron aluminid es with the composition Fe-45Al-5X-0.2B-0.1Zr (at%), where X stands fo r Ti, Cr, Mn, Fe, Co, Ni or Cu, were measured. With the exception of t he Mn-containing alloy, all alloys showed solid solution strengthening following a 1 week/673 K vacancy removal anneal. Densities, lattice p arameters and elastic constants were measured to determine vacancy con centrations as well as atomic size and modulus misfits. Although the s trengthening could not be well described by established theories for d ilute binary alloys, it could be reasonably well correlated with the m agnitude of the atomic size misfit of the ternary alloying additions. Copyright (C) 1996 Elsevier Science Limited