Dresden 2006 – wissenschaftliches Programm
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MM: Metall- und Materialphysik
MM 10: Intermetallic phases
MM 10.4: Vortrag
Montag, 27. März 2006, 17:15–17:30, IFW D
The Re-containing Inconel 706 Alloy: 3DAP Measurements — •Vitaliy Kindrachuk1, Nelia Wanderka1, John Banhart1, Dominique Del Genovese2, and Joachim Rösler2 — 1Hahn-Meitner-Institut, Glienicker Str. 100, 14109 Berlin, Germany — 2Institut für Werkstoffe, TU Braunschweig, Langer Kamp 8, 38106 Braunschweig, Germany
Inconel 706 is a wrought Ni-Fe base superalloy which is used for applications at service temperatures up to 600∘C. The good mechanical properties are caused by precipitation of intermetallic phases γ′ (L12 structure) and γ″ (DO22 structure). Re is known to stabilize the microstructure of Ni-based superalloys at higher temperature. Therefore, the influence of Re on Inconel 706 was investigated in the present study.
The microstructure evolution of 0.6 at.% Re-alloyed Inconel 706 was studied after ageing at 750∘C for 750 h and 5000 h by three-dimensional atom probe tomography and by TEM.
The modified stabilization heat treatment (MST) produces individual γ′ and γ″ precipitates and γ′/γ″ co-precipitates with average sizes of about 15 nm. Re concentrates mostly in the matrix (about 0.8 at. %), whereas the intermetallic phases contain 0.2 - 0.3 at.%. Large γ″ plates with sizes of about 50 - 100 nm are formed after ageing at 750∘C for 750 h. Their Re-content is very small (0.07 at.%).
After ageing for 5000 h only one type of precipitates remains, namely η plates embedded into the matrix. Therefore, the Re-alloyed Inconel 706 loses its mechanical properties. Unexpectedly Re does not stabilize the microstructure of the alloy at 750∘C.