Partner: W. Macek


Recent publications
1.Kopeć M., Gunputh U., Macek W., Kowalewski Z.L., Wood P., Orientation effects on the fracture behaviour of additively manufactured stainless steel 316L subjected to high cyclic fatigue, Theoretical and Applied Fracture Mechanics, ISSN: 0167-8442, DOI: 10.1016/j.tafmec.2024.104287, pp.1-20, 2024
Abstract:

In this paper, stainless steel 316L (SS316L) bars were additively manufactured (AM) in three orientations (Z – vertical, XY – horizontal, ZX45 – midway between vertical and horizontal) by using the Laser Powder Bed Fusion Melting (LPBF-M) method. The AM specimens were subjected to load control fatigue testing under full tension and compression (R = -1) at stress amplitudes ±350, ±400 and ±450 MPa. The XY and ZX45 printing orientations were found to significantly improve service life. Although similar strain response was found for each orientation when the same stress amplitude was applied, slightly different fracture mechanisms were identified during the post-mortem surface observations.

Keywords:

SS316L,stainless steel,fatigue,additive manufacturing,Laser Powder Bed Fusion Melting (LPBF-M)

Affiliations:
Kopeć M.-IPPT PAN
Gunputh U.-other affiliation
Macek W.-other affiliation
Kowalewski Z.L.-IPPT PAN
Wood P.-University of Derby (GB)
2.Macek W., Branco R., Podulka P., Kopeć M., Zhu S., Costa J., A brief note on entire fracture surface topography parameters for 18Ni300 maraging steel produced by LB-PBF after LCF, Engineering Failure Analysis, ISSN: 1350-6307, DOI: 10.1016/j.engfailanal.2023.107541, No.107541, pp.1-27, 2023
Abstract:

The concept of entire fracture surface investigation is helpful in explaining fatigue phenomena. In this paper, this method has been applied for 18Ni300 maraging steel using a 3D measurement system. Before post-mortem analysis, the specimens produced by laser beam powder bed fusion (LB-PBF) were tested under low-cycle fatigue (LCF) for eight strain amplitudes in the interval 0.3% to 1.0%. The attention was placed on the relationship between the fatigue features, represented by the strain level and the fatigue life as well as the fracture surface topography evaluated in the form of areal, volume and fractal dimension parameters. It was found that fatigue life predictions calculated using the core material volume Vmc, obtained with the entire fracture surface method were within a scatter band with factors of ±1.5. The present results can be useful for the analysis of damaged structural elements exposed to LCF, especially for materials produced by additive manufacturing (AM). The outcomes of this brief note are important for the development of other fractographic methods and validation of fatigue life evaluation procedures.

Keywords:

18Ni300 steel,laser beam powder bed fusion,low-cycle fatigue,surface metrology,entire fracture surface method,fractography,fractal dimension

Affiliations:
Macek W.-other affiliation
Branco R.-other affiliation
Podulka P.-other affiliation
Kopeć M.-IPPT PAN
Zhu S.-other affiliation
Costa J.-other affiliation