Influence of component geometry on residual stress in aluminium parts produced by laser powder bed fusion

Additive manufacturing (AM) enables parts with high geometric complexity including internal structures, leading to increasing interest of science and industry in the recent years. The mechanical properties of additively manufactured components, however, are still not completely understood and subject of intensive research efforts. In particular, residual stresses (RS) play an important role for the strength and fatigue properties. Therefore, RS distributions were investigated in various parts, fabricated from aluminium alloy powder (AlSi10Mg) using the Laser Powder Bed Fusion (LPBF) technique.

Residual stress fields in parts with different geometries, produced with the alloy AlSi10Mg, were determined using high-energy X-ray diffraction using high photon energy Hereon beamlines at PETRA III at Deutsches Elektronen Synchrotron (DESY). Angle-dispersive diffraction was used in transmission geometry and energy-dispersive techniques were used to obtain three-dimensional spatial resolution.

AM has a variety of process parameters. To improve the surface quality, the contour of each individual layer can be heat treated during construction. The manipulation of the residual stress achieved by the contour parameter was observed in various geometries. The influence of the contour parameter in different positions of different geometries is presented and the potential for improving the production process will be shown.