The effect of stress, temperature and loading direction on the creep behaviour of Ni-base single crystal superalloy miniature tensile specimens

被引:67
作者
Wollgramm, P. [1 ]
Buerger, D. [1 ]
Parsa, A. B. [1 ]
Neuking, K. [1 ]
Eggeler, G. [1 ]
机构
[1] Ruhr Univ Bochum, Inst Werkstoffe, Univ Str 150, D-44780 Bochum, Germany
关键词
Single crystal Ni-base superalloys; Creep anisotropy; Stress and temperature dependence of creep rates; Elementary softening and deformation mechanisms; Double minimum (DM) creep; INTERFACIAL DISLOCATION NETWORKS; GAMMA-PHASE; GAMMA/GAMMA'-INTERFACES; DAMAGE ACCUMULATION; UNIAXIAL-STRESS; STACKING-FAULTS; MICROSTRUCTURE; DEFORMATION; CMSX-4; ANISOTROPY;
D O I
10.1080/09603409.2016.1186414
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
In the present work, we use a miniature test procedure to investigate the tensile creep behaviour of the single crystal superalloy ERBO1. We test precisely oriented [0 0 1], [1 1 0] and [1 1 1] creep specimens and determine the stress and the temperature dependence of characteristic creep rates in limited stress and temperature regimes, where the stress and temperature dependence of characteristic creep rates can be well described by power law and Arrhenius type of relations, with stress exponents n and apparent activation energies Q(app).n-values increase with stress and decrease with temperature. Q(app)-values, on the other hand, increase with increasing temperature and decrease with increasing stress. Creep curve shapes gradually evolve from the high temperature low stress to the low temperature high stress (LTHS) regime. This implies that there is a gradual change in elementary deformation and softening mechanisms, which is qualitatively confirmed using transmission electron microscopy. While at high temperatures different loading directions only have a moderate influence on creep, there is a very strong effect of loading direction at low temperatures. The [1 1 0] tests show the fastest deformation rates and the shortest rupture times. In the LTHS creep regime, we confirm the double minimum (DM) type of creep behaviour, which was previously reported but never explained. Further work is required to rationalise DM-creep. The implications of this type of creep behaviour on scatter and on extrapolation of creep data is discussed in the light of previous results published in the literature.
引用
收藏
页码:346 / 360
页数:15
相关论文
共 84 条
  • [1] [Anonymous], 2013, Acta Materialia
  • [2] [Anonymous], MAT SCI TECHNOLOGY
  • [3] [Anonymous], MATERIALWISSENSCHAFT
  • [4] [Anonymous], CREEP DEFORMATION RU
  • [5] [Anonymous], SUPERALLOYS
  • [6] [Anonymous], DEV GAMMA GAMMA PRIM
  • [7] [Anonymous], HIGH TEMP MAT POWER
  • [8] [Anonymous], 1993, THESIS
  • [9] [Anonymous], DISLOCATIONS SOLIDS
  • [10] [Anonymous], THESIS