• Futoma, Magdalena
• Reed, Roger C.
• Roebuck, Bryan
• Tang, Yuanbo T.
• Schwalbe, Caspar

Abstract

<jats:title>Abstract</jats:title><jats:p>This study concerns the quasi-static and time-dependent mechanical behavior obtained <jats:italic>via</jats:italic> the miniaturized electro-thermal mechanical testing (ETMT) approach for single crystal (SX) and conventional cast Mar-M-247 superalloy. The experimental outcome was benchmarked against standardized testing procedures. It is found that tensile yielding behavior can be captured accurately by the ETMT approach up to 1100 <jats:inline-formula><jats:alternatives><jats:tex-math>^</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mrow /><mml:mo>∘</mml:mo></mml:msup></mml:math></jats:alternatives></jats:inline-formula>C, provided the appropriate type of thermocouple (T/C) is chosen. Furthermore, creep rupture behavior is underestimated by the miniaturized set-up. High repeatability of the rupture time was obtained for the SX case, whereas a significant scatter was observed for the conventional cast case. The discrepancies are assessed in detail; discussion centers around analytical and practical considerations, such as temperature uncertainty due to parasitic voltage and the choice of T/C, microstructural change as a result of the Joule heating, representative gauge volume, and strain rate non-linearity. Consequently, the applicability and limits of the miniaturized approach are examined critically, and improvements were suggested where appropriate.</jats:p>

Topics

• impedance spectroscopy
• single crystal
• creep
• superalloy