Phase transformations in nanocrystalline alloys

✍ Scribed by A.Reza Yavari

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 613 KB
• Volume: 179-180
• Category: Article
• ISSN: 0921-5093
• DOI: 10.1016/0921-5093(94)90157-0

✦ Synopsis

In this paper we study metastable phases obtained in nanocrystalline morphology. After considering nanocrystallization under heavy deformation, we discuss polymorphous order to disordered phase transformations during nanocrystallization of L12-Ni3Al-type alloys, polymorphous nanocrystalline to amorphous phase transformations and the thermodynamics of formation of nanocrystalline supersaturated solid solutions of immiscible elements such as CuFe. While many results have recently appeared on structural evolutions during nanocrystallization, few studies have been devoted to the reverse process of return to equilibrium phase distributions. Here we discuss the thermally activated polymorphous disorder to order (7-f.c.c. to y-L12) transformation in nanocrystalline intermetallics, the nanocrystallization of phaseseparating amorphous alloys such as Pda0Pbr0, nanocrystallization of FeSiBNbCu-type soft magnetic alloys and the thermal decomposition of metastable nanocrystalline alloys in spinodal systems such as CuFe.