A combined CP theory and TCD for predicting fatigue lifetime in single-crystal superalloy plates with film cooling holes

Wei

et al. 2019

Metals

In this paper, the viewpoint that maximum resolved shear stress corresponding to the two slip systems in a nickel-based single crystal high-temperature fatigue experiment works together was put forward. A nickel-based single crystal fatigue life prediction model based on modified resolved shear stress amplitude was proposed. For the four groups of fatigue data, eight classical fatigue life prediction models were compared with the model proposed in this paper. Strain parameter is poor in fatigue life prediction as a damage parameter. The life prediction results of the fatigue life prediction model with stress amplitude as the damage parameter, the fatigue life prediction model with maximum resolved shear stress in 30 slip directions as the damage parameter, and the McDiarmid (McD) model, are better. The model proposed in this paper has higher life prediction accuracy.

Section: Discussionmentioning

confidence: 99%

“…It takes a long time to calculate the stress and strain of single crystal hollow blades with complex cooling structures. In addition, the program in [18] is unstable and is not easy to apply in engineering. Ref.…”

Section: Discussionmentioning

confidence: 99%

A Fatigue Life Prediction Model Based on Modified Resolved Shear Stress for Nickel-Based Single Crystal Superalloys

Wei

et al. 2019

Metals

“…Li et al [11] found in the study of FGH4096 blade materials that the cooling rate after solution treatment determined the morphology and distribution of the precipitated precipitation phases. A faster cooling rate could make the precipitated precipitation phases have better morphology and a narrower channel of matrix phase, which improved the precipitation effect of Orowan [12][13][14], and effectively hindered dislocation movement in matrix phase; thus, the material could be improved. The creep properties were improved at 704 • C/690 MPa.…”

Section: Introductionmentioning

confidence: 99%

Influences of the Heating and Cooling Rates on the Dissolution and Precipitation Behavior of a Nickel-Based Single-Crystal Superalloy

Cheng

et al. 2019

Metals

The effects of the heating rate before solution treatment, and the cooling rate after solution treatment on the morphological distribution and evolution of the precipitation phase of nickel-based single crystal superalloy were studied. The dissolution, precipitation, and growth of the precipitation phase and the matrix phase during heat treatment were analyzed by the means of high-power scanning electron microscopy. The results show that the morphology of the precipitated phase has nothing to do with the distribution of the precipitated phase and the heating rate in the heating process, but the cooling rate in the cooling process affects the shape, size, and distribution of the precipitated phase. The faster the cooling rate, the smaller the precipitated phase is, the more irregular the shape is, the smaller the equivalent edge length is, and the smaller the channel width of the matrix phase is.

Materialwissenschaft Werkst

“…However, due to change in the geometry, these components can be subjected to a com-plex stress state. Notched specimens are widely used to investigate the effect of multi-axial stress state on creep deformation and rupture behavior of the material [3][4]. Therefore, it is important to estimate the creep damage behavior and rupture life of the notched specimens with different radius under multi-axial stress state.…”

Section: Introductionmentioning

confidence: 99%

Creep properties of a U‐type notch plate in Ni‐based superalloy

Gan

Zhou

Pei

et al. 2019

In the present investigation, the effect of notch on creep rupture behavior and creep rupture life of a Ni-based superalloy has been assessed by performing creep tests on smooth and U-notched plate specimen under 0°C. The finite element analysis coupled with continuum damage mechanics are carried out to understand the stress distribution across the notch throat and the creep damage evolution under multi-axial stress state. The creep rupture life of U-notched specimen is much larger than that of plane plate specimen under the same stress condition, indicating that there is a strengthening effect on notch specimen. Creep rupture life increases with increasing the notch radius, the smaller notch radius can induce the creep rupture easier. The effect of notch on the creep damage is also studied. It is found that the location of the maximum creep damage and the maximum equivalent creep strain initiates first at the notch root and gradually moves to the inside as the notch radius increases. Keywords:Ni-based superalloy / notch radius / creep rupture life / creep damage / finite element analysis Schlüsselwörter: Nickelbais-Superlegierung / Kerbradius / Kriechbruch-Lebensdauer