In:
International Journal of Materials Research, Walter de Gruyter GmbH, Vol. 105, No. 3 ( 2014-03-11), p. 225-231
Abstract:
Thermomechanical fatigue cyclic loading tests have been carried out along the 〈 001 〉 orientation and the formation of twins during thermomechanical fatigue processing has been studied in detail in a nickel-base single crystal TMS-82 superalloy. The twinning dislocation is determined to be 1/6 〈 112 〉 in the γ′ phase except for the 1/3 〈 112 〉 dislocation, which operates on every successive {111} plane. The 1/6 〈 112 〉 twinning dislocations can move independently in both γ and γ′ phases. Although movement of a single 1/6 〈 112 〉 twining dislocation may destroy the ordering of γ′ phase, its existence is rationalized on the basis of crystallographic analysis. The movement of a 1/3 〈 112 〉 dislocation on a single {111} plane will lead to a high-energy stacking sequence of head-to-head of two neighboring {111} layer atoms in the L1 2 structure. Pre-existing dislocations have a significant effect on the growth of deformation twins. In the dislocation-free area, the twin can propagate without any notable impediment to lead to a twin plate with equal width. High dislocation density may hinder the propagation of twins to varying degrees.
Type of Medium:
Online Resource
ISSN:
2195-8556
,
1862-5282
Language:
English
Publisher:
Walter de Gruyter GmbH
Publication Date:
2014
detail.hit.zdb_id:
2232675-3
detail.hit.zdb_id:
2128058-7
detail.hit.zdb_id:
203021-4
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