Crystalline structure and morphology of X phase in Cu Al-Ni-Mn-Ti alloy

摘要

The composition, morphology, crystalline structure and formation and evolution of X phase in a Cu 12.3Al 2Ni 2Mn 1Ti alloy were studied. The results show that the X phase is a Ti rich phase with atomic ratio of (Cu+Ni)∶ Ti∶Al=2∶1∶1 and DO 3 or L2 1 structure; it is directly formed in the liquid phase by crystallization in the process of solidification of the alloy; there forms free particle X phase through the progressive dissolution and breakdown of the inter dendritic microstructure in the following homogenization process. The X phase has three different morphologies, i.e. X L, X LS and X S, whose contents in the matrix rely on the heat treatment conditions. [