TEM AND X-RAY DIFFRACTION STUDIES OF STRUCTURE CHANGES DURING MECHANICAL ALLOYING OF TiAl AND TiAIMn ALLOYS

摘要

X-ray diffraction and analytical TEM techniques were used in order to analyse the phase transformations and structure changes after mechanical alloying of TiAl and TiAIMn alloys. After 40 hours of milling the formation of α-Ti(Al) solid solution and amorphous phase has been observed both in binary and ternary alloys. The amount of amorphous phase increases with addition of Mn. The microstructure of binary alloy was composed of nano layers with the average width of about 50 nm. Microstructure of ternary alloys were also of the layered type but the layers were curved and wider. The addition of Mn caused introduction of chemical heterogeneity into the layers.