Effect of a sharp gradient of concentration on nucleation of intermetallics at interfaces between polycrystalline layers

✍ Scribed by F. Hodaj; P.J. Desré

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 624 KB
• Volume: 44
• Category: Article
• ISSN: 1359-6454
• DOI: 10.1016/1359-6454(96)00085-7

✦ Synopsis

Recent works on reaction kinetics in bimetallic multilayers have demonstrated that the unidirectional sharp concentration gradient, which develops as interdiffusion proceeds at the interface, is able to delay or to inhibit nucleation of intermetallics. A thermodynamic and kinetic approach is proposed in order to explain such a phenomenon. The existence of a critical concentration gradient, beyond which nucleation is suppressed, is found to be strongly dependent on the atomic transport in both intermetallics and metastable solid solution and more specifically on the activation energy of each phase. Consequently, the temperature appears to be the most significant variable controlling the existence and the value of a critical concentration gradient.