首页|Room-temperature low-cycle fatigue behaviour of cast and additively manufactured IN939 superalloy
Room-temperature low-cycle fatigue behaviour of cast and additively manufactured IN939 superalloy
扫码查看
点击上方二维码区域，可以放大扫码查看
原文链接
NETL
NSTL
Elsevier
The present study compares the fatigue properties of IN939 superalloy manufactured conventionally by casting and additively by laser powder bed fusion (L-PBF). To investigate the influence of specimen orientation, i.e. load-to-build direction, and heat treatment on fatigue properties, 4 batches of additively manufactured specimens were prepared: vertically and horizontally oriented batches with either as-built microstructure (non-treated) or aged γ/γ' microstructure. Cylindrical specimens were machined from the cast rod and printed blocks, and subjected to low-cycle fatigue loading at room temperature. Fatigue testing was conducted in total strain amplitude control within ε_a = 0.27-1% with a constant strain rate of 2·10~(-3) s~(-1). Scanning and transmission electron microscopy techniques were used to analyse the specimens before and after testing. Out of all tested batches, horizontal aged L-PBF IN939 exhibited the best stress-life fatigue properties, while vertical non-treated L-PBF specimens showed the largest resistance to cyclic plastic straining. Plastic strain localization occurred in the form of persistent slip bands, which led to fatigue crack initiation at the specimen surface. The high stresses associated with the L-PBF batches favour interdendritic and intergranular cracking, increasingly so with higher batch strength. However, the cracking mechanism does not significantly affect the low-cycle fatigue life, which is primarily determined by the crack initiation phase.
Laser powder bed fusionDamage mechanismsDeformation behaviourCyclic plasticityPlastic strain localization
T. Babinsky、I. Sulak、M. Galikova、I. Kubena、J. Poloprudsky、L. Nahlik
展开 >
Institute of Physics of Materials, Czech Academy of Sciences, Zizkova 513/22, 616 00, Brno, Czech Republic
NETL
NSTL
Elsevier
