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The influence of a delay time at the maximum temperature on the number of cycles
for the macrocrack initiation for two thermal loading programs was investigated for two
single-crystal nickel-based superalloys VIN3 and ZhS32. An analytic approximation of a
delay time influence was proposed. Comparison of computational results and analytic formula
on the base of constitutive equations with the experimental data was performed for considered
single-crystal superalloys and showed a good accuracy. Influence of several mechanical
constants of nickel alloy on thermal fatigue strength is presented and discussed. The influence
of crystallographic orientation of the corset sample on the thermal fatigue durability with
delay times for various thermal loading programs and different single-crystal nickel
superalloys was investigated.
Keywords: thermal fatigue, single-crystal nickel-based superalloy, deformation criterion, corset sample, crystallographic orientation, finite element modeling, analytic approximation |
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