Improvement of the cantilever test geometry deflection measurement method to assess residual stresses in laser powder bed fusion

Abstract Laser powder bed fusion (L-PBF) processes allow for the creation of advanced 3D parts that are difficult to achieve through conventional manufacturing. Defects such as part deformation are a critical issue in L-PBF and seriously affect the industrial adoption of metal additive manufacturing (AM) processes for critical applications. The research community has widely accepted the deformation measurement of known geometries, such as cantilevers or bridges, for the assessment of residual stresses. In this study, quantitative measurements are obtained using a 3D optical scanner on cantilevers with different geometries, in order to study the effect of bar thickness on deformation. Furthermore, this experimental study aims to investigate cantilever deflection measurement methods and compare the obtained deviation parameters. The findings reveal that, in case of cantilever specimens, flatness and curvature attributes measured on surface are more reliable than maximum vertical deflection. The part height plays a primordial role on the deflection, the distortion changes in inverse proportion to the cantilever’s bar thickness.