EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

The usual characterization of the fatigue behavior of metallic materials based on constant amplitude tests requires high experimental efforts. However, for dimensioning of highly loaded components a sound knowledge of fatigue strength as well as cyclic deformation behavior of the used material is a prerequisite. Moreover, the influence of microstructural defects, i.e., pores and non-metallic inclusions, has to be considered for reliable design.
To efficiently determine the cyclic properties of metallic materials and thus, significantly reduce experimental effort, the short-time procedure PhyBaLCHT, which is based on cyclic indentation tests (CITs) and is explained in detail in [1], can be used. By analyzing the cyclic deformation behavior in CITs, the cyclic hardening potential of a material can be characterized. Investigations on differently heat-treated copper alloyed steel as well as additively manufactured 316L show, that the cyclic hardening potential determined in CITs correlates well with the defect tolerance of a material, obtained in common uniaxial fatigue tests. In addition to that, the results obtained at copper alloyed steel indicate that this experimental approach can further be used to asses the fatigue strength of different material conditions. Note that in CITs multiaxial stresses are applied beneath the indenter, which has to be considered for estimation of the fatigue behavior at uniaxial stress conditions. However, in further investigations on differently heat-treated 42CrMo4 [1], the cyclic deformation curves obtained in uniaxial fatigue tests with cyclic compressive stresses (R=-∞) correlate well with the cyclic deformation behavior observed in CITs. This underlines the applicability of this short-time procedure for the characterization of the cyclic properties of a material.
The presented results demonstrate, that the short-time procedure PhyBaLCHT is a powerful means to qualitatively characterize the relevant cyclic properties of metallic materials.

[1] Blinn et al..: Int. J. Fat. (119), 2019.