Abstract
New Ti-44Al-5Nb-3Cr-1.5Zr(at%) intermetallic alloy, microstructured by float zone (FZ) processing, was subjected to slow dilatometric heating from the room temperature (RT) up to solidus. The evolution of linear thermal expansion coefficient (LTEC) has been compared with the phase transformation path of the alloy within the polythermal section of phase diagram calculated with ThermoCalc®. Thus, the characteristic temperatures of predicted phase transitions were experimentally verified. Results from dilatometry, EDX microanalysis, scanning and transmission electron microscopy have shown that thermodynamic database used is poorly describe the phase transformations in β-stabilized TiAl alloy at the temperatures lower than ~1000°C. While at higher temperatures the perfect correspondence was observed between the ThermoCalc® predictions and dilatometric data. The features of verified phase transformation behavior are discussed in view of comparison with those of “classic” Ti-43.5Al-4Nb-1Mo-0.1B TNM™ alloy. It is assumed that TiAl(Nb, Cr, Zr) alloy is fundamentally more favorable for high-temperature FZ-microstructuring and performance.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
