TEM observations of a rapidly solidified Al–Ti–C alloy

Abstract

In the present work, the microstructure of melt-spun Al–10Ti–1C alloy has been characterized using X-ray diffraction (XRD) and transmission electron microscopy (TEM). The phases present in the melt-spun alloy are identified to be α-Al solid solution, the equilibrium tetragonal TiAl 3 and hexagonal TiC by XRD and electron diffraction. Both large and small TiAl 3 particles are observed in melt-spun Al–10Ti–1C alloy. The large TiAl 3 particles, ∼1 μm in size, exhibit a homogeneous single-phase structure. The small TiAl 3 particles are blocky, ∼0.1–0.2 μm in size. Some of them are a homogeneous single phase but some of them exhibit an ultrafine nanocellular structure. Polygonal TiC particles, ∼1.2–1.5 μm in size, are found in melt-spun Al–10Ti–1C alloy. Both TiAl 3 and TiC particles are found to act as heterogeneous sites nucleating α-Al grains in the melt-spun alloy. The reasons for the formation of the microstructure of melt-spun Al–10Ti–1C alloy have also been discussed.