On the Temperature Dependence of Creep Behavior of Ni‐Base Single Crystal Superalloys

Wollgramm, P.; Wu, Xiaoxiang; Eggeler, Gunther

doi:10.1002/9781119075646.ch76

Cited by 4 publications

(1 citation statement)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The minimum creep rate (

{\dot{ε}}_{\min}

) can be obtained from Figure 4C and summarized in Figure 4D.

{\dot{ε}}_{\min}

is an important reference index for design purposes, and is related to the applied stress ( σ app ) by the relationship: 27–29

{\dot{ε}}_{\min} = C_{2} σ_{app}^{m_{2}},

where C 2 is a constant and m 2 is a stress exponent. All data can be represented by a Norton law (the red dash line in Figure 4D) with a stress exponent m 2 = 8.6 and Equation () can be written as

{\dot{ε}}_{\min} = 1.12 e^{- 27} σ_{app}^{8.6}

.…”

Section: Resultsmentioning

confidence: 99%

The dependence of stress and strain rate on the deformation behavior of a Ni‐based single crystal superalloy at 1050°C

Ding

Bei

et al. 2021

Int Journal of Mech Sys Dyn

View full text Add to dashboard Cite

Ni-based single crystal (SX) superalloys are important high-temperature materials used for manufacturing turbine blades in aero-engines. During service under combinational impacts of temperature and stress, the SX superalloy may reach its life due to plastic deformation, which normally accompanies time-dependent microstructural degradation.To reveal this dynamically mechanical response, tensile tests at 1050°C are carried out to record stress-strain curves at five stain rates as well as creep curves at four applied stresses. Deformed microstructures and defects have been analyzed to understand mechanical behaviors and the underlying mechanism by using advanced scanning electron and scanning transmission electron microscopes. Results show that the deformation mode of the alloy strongly depends on the strain rates/applied stresses under mechanical loading. The dislocation density inside the γ phase is extremely low at all tests, indicating that the γ phase is relatively weak and ready to flow at this temperature even at a very fast strain rate. The deformation behavior of the γ′ phase is much complicated. At fast strain rates or high applied stresses, the dislocation density in the γ′ phase is very high, contributing to high-stress requirements to deform the material. At slow strain rates or low applied stresses, rafting microstructures develop and the deformation mode becomes directional coarsening/diffusion-dominated. Our results demonstrate a comprehensive understanding of the deformation mechanism of Ni-based SX superalloys, which may provide lifetime prediction of the mechanical failure, as well as the database for superalloy applications in mechanical systems.

show abstract

“…The minimum creep rate (

{\dot{ε}}_{\min}

) can be obtained from Figure 4C and summarized in Figure 4D.

{\dot{ε}}_{\min}

is an important reference index for design purposes, and is related to the applied stress ( σ app ) by the relationship: 27–29

{\dot{ε}}_{\min} = C_{2} σ_{app}^{m_{2}},

where C 2 is a constant and m 2 is a stress exponent. All data can be represented by a Norton law (the red dash line in Figure 4D) with a stress exponent m 2 = 8.6 and Equation () can be written as