Experimental investigation on low cycle fatigue and creep-fatigue interaction of DZ125 in different dwell time at elevated temperatures

Abstract The low cycle fatigue (LCF) and creep–fatigue tests have been conducted with directionally solidified nickel-based superalloy DZ125 at 850 and 980 °C to study the creep–fatigue interaction behavior of alloy with different dwell time. On the average, the life of creep–fatigue tests are about 70% less than the life of LCF tests under the same strain range at 850 °C. The life of creep–fatigue decreases as dwell time increases, but the life of this alloy was almost unchanged when dwell time exceeds a critical value at 850 °C. Scanning electron microscope (SEM) analyses of the fracture revealed that the fracture modes were influenced by different way of loading. In case of LCF, the primary fracture mode was transgranular, while in case of creep–fatigue, the primary fracture mode was mixed with transgranular and intergranular. There were also obvious different morphologies of surface crack between LCF and creep–fatigue.

[1]  D. McDowell,et al.  Effect of pre-exposure on crack initiation life of a directionally solidified Ni-base superalloy , 2009 .

[2]  Jong-Taek Yeom,et al.  Continuum damage mechanics-based creep-fatigue-interacted life prediction of nickel-based superalloy at high temperature , 2007 .

[3]  J. Tien,et al.  Creep-fatigue behavior of directionally solidified intermetallic Ni3Al (B,Hf) at 450°C , 1987 .

[4]  Y. Jinjiang,et al.  High temperature low cycle fatigue behavior of a directionally solidified Ni-base superalloy DZ951 , 2008 .

[5]  J. Chaboche,et al.  A cohesive zone model for fatigue and creep–fatigue crack growth in single crystal superalloys , 2009 .

[6]  Tiedo Tinga,et al.  Time-incremental creep–fatigue damage rule for single crystal Ni-base superalloys , 2009 .

[7]  A. Pineau,et al.  High temperature fatigue of nickel-base superalloys - A review with special emphasis on deformation modes and oxidation , 2009 .

[8]  Rongqiao Wang,et al.  Experimental study on creep–fatigue interaction behavior of GH4133B superalloy , 2009 .

[9]  Y. Yamazaki,et al.  Creep-fatigue small crack propagation in a single crystal Ni-base superalloy, CMSX-2. Microstructural influences and environmental effects , 1999 .

[10]  H. Maier,et al.  Creep–fatigue interaction of the ODS superalloy PM 1000 , 2009 .

[11]  D. Mowbray,et al.  Effect of material characteristics and test variables on thermal fatigue of cast superalloys. A review , 1974 .

[12]  K. Sadananda,et al.  Crack growth in a directionally solidified ψ/ψ′ + δ eutectic alloy under creep and fatigue conditions , 1979 .

[13]  D. Smith,et al.  Development of an anisotropic constitutive model for single crystal superalloy for combined fatigue and creep loading , 1998 .

[14]  P. Reed,et al.  Effects of mixed mode loading on fatigue and creep-fatigue in SRR-99 single crystals , 2005 .

[15]  Z. Hu,et al.  High temperature creep and low cycle fatigue of a nickel-base superalloy , 2010 .

[16]  David L. McDowell,et al.  Transversely isotropic viscoplasticity model for a directionally solidified Ni-base superalloy , 2006 .