Creep in Cast MAR – M247 Nickel – Base Superalloy

0450437 - ÚFM 2016 RIV FR eng A - Abstract
Kvapilová, Marie - Kuchařová, Květa - Král, Petr - Hrbáček, K. - Sklenička, Václav
Creep in Cast MAR – M247 Nickel – Base Superalloy.
BOOK OF ABSTRACTS. 13th International Conference on Creep and Fracture of Engineering Materials and Structures. Toulouse: Institut Carnot CIRIMAT, 2015. s. 111-112.
[CREEP 2015 - International Conference on Creep and Fracture of Engineering Materials and Structures /13./. 31.05.2015-04.06.2015, Toulouse]
R&D Projects: GA MŠMT(CZ) ED1.1.00/02.0068; GA TA ČR(CZ) TA04011525
Institutional support: RVO:68081723
Keywords : MAR * creep * deformation mechanisms
Subject RIV: JG - Metallurgy

The MAR – M247 superalloy exhibits a variety of excellent characteristics, including good castability, good strength levels, superior creep properties, and hot corrosion resistance at high temperatures. The material underwent hot isostatic pressing (HIP) and proper heat treatment. The microstructure was dendritic with coarse grain size of about 0.8 mm and the high volume fraction of strengthening phase  (around 60%) heterogeneously distributed in the  matrix. Standard uniaxial tensile creep tests were carried out to the rupture. The creep tests were performed at applied stresses ranging from 100 to 750 MPa and at temperatures from 800 to 1000°C. The determined values of stress exponent n correspond to the power-law creep regime and suggest dislocation glide a climb as a dominating creep deformation mechanisms. Fractographic observations by SEM indicated that at lower test temperature is the fracture of MAR-M247 superalloy of intergranular fracture mode. With increasing test temperature a mixture of intergranular (interdendritic) and transgranular fracture modes was observed.
Permanent Link: http://hdl.handle.net/11104/0251770