Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1576153 | Materials Science and Engineering: A | 2013 | 8 Pages |
Abstract
In-situ stair case loading experiments at 500 °C using neutron diffraction have been carried out on two γⲠstrengthened polycrystalline nickel base superalloys, RR1000 and Udimet 720LI. In order to study the effect of γⲠparticle size, uni-modal γⲠsize distributions were generated in both alloys. Both alloys showed signs of dynamic strain aging (DSA) although the strain bursts were far more significant in RR1000 than Udimet 720LI. The neutron diffraction experiment revealed load partitioning between γ and γⲠin the case of the coarse γⲠmicrostructure but not in the fine γⲠmicrostructure. When load partitioning occurred, γⲠpicked up significantly larger elastic strains during a DSA related strain burst than the γ matrix, indicating that mainly the matrix phase deforms plastically during such an event. The peak broadening data confirmed this. Subsequent to the strain burst, a reduction in the elastic strain partitioning was observed indicating preferred yielding of the γⲠphase during this stage. The differences in DSA detected between RR1000 and Udimet 720LI are discussed in terms of possible contribution of the various alloying elements.
Related Topics
Physical Sciences and Engineering
Materials Science
Materials Science (General)
Authors
Benedict M.B. Grant, Elisabeth M. Francis, João Quinta da Fonseca, Michael Preuss, Mark R. Daymond,