Title :
Microstructure control in high Ti NbTi alloys
Author :
Lee, P.J. ; McKinnell, J.C. ; Larbalestier, D.C.
Author_Institution :
Appl. Supercond. Center, Wisconsin Univ., Madison, WI, USA
fDate :
3/1/1989 12:00:00 AM
Abstract :
The microstructures of five high-Ti NbTi alloys (Nb49-62-wt.%Ti) and a ternary Nb-54-wt.%Ti, 4-wt.%Zr alloy have been observed following heat treatments of 80 h at 420°C at prestrains of between 8.3 and 12.6. It was found that increasing prestrain suppressed the formation of deleterious Widmanstatten α-Ti and ω phases and that the higher the Ti content, the higher the prestrain required for elimination of these forms of precipitation. The Zr addition increased the precipitation rate and reduced the precipitate size without promoting the formation of Widmanstatten α-Ti or ω
Keywords :
Widmanstatten structure; alloying additions; heat treatment; niobium alloys; precipitation; titanium alloys; transmission electron microscope examination of materials; type II superconductors; zirconium alloys; ω phases; 420 degC; 80 h; Nb-Ti-Zr; NbTi alloys; TEM; Widmanstatten phases; alpha phase; heat treatments; microstructures; precipitate size; precipitation; prestrains; Grain boundaries; Heat treatment; Microstructure; Niobium compounds; Titanium alloys; Titanium compounds; Transmission electron microscopy;
Journal_Title :
Magnetics, IEEE Transactions on
