Peritectic Coupled Growth Solidification-a Review

Initiation and growth mechanisms of peritectic coupled growth (PCG) structures have been reviewed to clarify parameters that play a significant role in PCG formation and stability. Three important alloys of Fe-Ni, Ni-Al and Ti-Al have been studied to reveal mechanisms contributing to PCG formation. Types of PCG, the stability of lamellar coupled growth and their morphological behavior are strongly dependent on G/V ratio (G: thermal gradient, V: growth rate), lamellar spacing and composition. Analogy between peritectic coupled growth (PCG) and eutectic coupled growth (ECG) is also a point of interest in this study. Further investigations in Ni-Al and Cu-Sn are necessary to clarify the PCG formation (nucleation/growth mechanism) in conventional G/V versus composition diagram.