TY - GEN
T1 - HIGH TEMPERATURE DEFORMATION OF EXTREMELY FINE GRAINED MA754 AND MA6000.
AU - Gregory, J. K.
AU - Gibeling, J. C.
AU - Nix, W. D.
PY - 1983
Y1 - 1983
N2 - The mechanical properties of the oxide dispersion strengthened nickel base alloys MA754 and MA6000 have been investigated. Due to the extremely fine grain sizes involved (0. 67 mu m for MA754 and 0. 25 mu m for MA6000), strain rates of interest were unusually high. The alloy MA6000 is superplastic, exhibiting a maximum elongation of over 300%, with a maximum m-value of 0. 51. MA754 has a maximum m-value of 0. 37, with a maximum elongation of 200%. This difference is attributed to the difference in initial dislocation densities. MA754, with an initial dislocation density of 1. 0 minus 2. 0 multiplied by 10**1**4 m/m**3, undergoes partial recrystallisation and grain growth during deformation at all but the highest strain rates. The inhomogeneities thus generated lead to failure. In contrast, the microstructure of MA6000, having an initial dislocation density of 0. 3 multiplied by 10 **1**4 m/m**3 is more stable. Only slight grain growth is observed, and no evidence of dynamic recrystallisation is found.
AB - The mechanical properties of the oxide dispersion strengthened nickel base alloys MA754 and MA6000 have been investigated. Due to the extremely fine grain sizes involved (0. 67 mu m for MA754 and 0. 25 mu m for MA6000), strain rates of interest were unusually high. The alloy MA6000 is superplastic, exhibiting a maximum elongation of over 300%, with a maximum m-value of 0. 51. MA754 has a maximum m-value of 0. 37, with a maximum elongation of 200%. This difference is attributed to the difference in initial dislocation densities. MA754, with an initial dislocation density of 1. 0 minus 2. 0 multiplied by 10**1**4 m/m**3, undergoes partial recrystallisation and grain growth during deformation at all but the highest strain rates. The inhomogeneities thus generated lead to failure. In contrast, the microstructure of MA6000, having an initial dislocation density of 0. 3 multiplied by 10 **1**4 m/m**3 is more stable. Only slight grain growth is observed, and no evidence of dynamic recrystallisation is found.
UR - http://www.scopus.com/inward/record.url?scp=0020899676&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:0020899676
SN - 8755009468
T3 - Proceedings of the Riso International Symposium on Metallurgy and Materials Science
SP - 263
EP - 268
BT - Proceedings of the Riso International Symposium on Metallurgy and Materials Science
A2 - Bilde-Sorensen, J.B.
A2 - Hansen, N.
A2 - Horsewell, A.
A2 - Leffers, T.
A2 - Lilholt, H.
PB - Riso Natl Lab
ER -