Crystalline structure and morphology of Xphase in Cu-Al-Ni-Mn-Ti alloy①
(Department of Materials Science and Engineering, Central South University,
Changsha 410083, P.R.China)
Changsha 410083, P.R.China)
Abstract: The composition, morphology, crystalline structure and formation and evolution ofXphase in a Cu-12.3Al2Ni-2Mn-1Ti alloy were studied. The results show that theXphase is a Ti-rich phase with atomic ratio of (Cu+Ni)∶ Ti∶Al=2∶1∶1 and DO3or L21structure; it is directly formed in the liquid phase by crystallization in the process of solidification of the alloy; there forms free particleXphase through the progressive dissolution and breakdown of the inter-dendritic microstructure in the following homogenization process. TheXphase has three different morphologies, i.e.XL, XLSandXS, whose contents in the matrix rely on the heat-treatment conditions.
Key words: Cu-Al-Ni-Mn-Ti alloy;Xphase; crystalline structure; morphology