Now showing 1 - 2 of 2
  • Publication
    Machinability study in orthogonal cutting of additively manufactured Inconel 718 with specifically induced porosity
    ( 2024-02-01) ;
    Li, Yupeng
    ;
    Boseila, Jonas
    ;
    ; ;
    Schleifenbaum, Johannes Henrich
    In comparison to conventional manufacturing technologies, additive manufacturing (AM) offers great design freedom, the integration of functions into components, new lightweight design concepts and high material efficiency. In aerospace and turbomachinery, this technology is increasingly coming into focus, especially the laser-based powder bed fusion of metals (PBF-LB/M) process. PBF-LB/M is already used for some aerospace components, which are often exposed to high thermal and mechanical loads. Dependent on the component geometry, support structures are required for AM, which then usually have to be removed by machining. One suitable support structure is the use of material with specifically induced porosity. This ensures good heat dissipation and thus homogeneous component properties, high retention forces and short process times in PBF-LB/M. However, the machinability of porous, additively manufactured material has hardly been researched so far. One preliminary investigation of milling porous, additively manufactured Inconel 718, though, showed significantly poorer machinability of the porous material compared to the dense material. To further examine this phenomenon, this paper presents the results of fundamental machinability studies with porous, additively manufactured Inconel 718 in orthogonal cutting. The investigations with tungsten carbide cutting tools on a special fundamental test rig include the analysis of the cutting force, the chip geometry, the chip temperature and the surface quality. The research results provide explanations for the poorer machinability of the porous material and derived approaches for improving the machinability in future studies.
  • Publication
    Machinability analysis for milling of additively manufactured Inconel 718 with specifically induced porosity
    ( 2022) ;
    Hermsen, Steffen
    ;
    Kirchmann, Stephan
    ;
    ; ;
    Schleifenbaum, Johannes H.
    Compared to conventional manufacturing technologies, additive manufacturing (AM) offers great design freedom, the integration of functions into components, new lightweight construction concepts and high material efficiency. This technology is increasingly coming into focus in aerospace and turbomachinery engineering, especially the Laser Powder Bed Fusion (LPBF) process. LPBF is already being used for some aerospace components that are often subject to high thermal and mechanical loads. Depending on the component geometry, support structures are required for additive manufacturing, which then have to be removed, usually by machining. Among others, the use of material with specifically induced porosity is suitable as a support structure. This ensures good heat dissipation and thus homogeneous component properties, high retention forces and short process times in the LPBF process. However, the machinability of porous, additively manufactured material has hardly been researched to date. This paper therefore presents the results of machinability investigations with porous, additively manufactured Inconel 718. The investigations included the analysis of active cutting force, cutting tool wear, surface finish and chip geometry in the milling process with tungsten carbide cutting tools. It was found that with the porous material, the dominant type of wear is early starting chipping of the cutting tool edges. The active force decreases with increasing porosity. Partial smearing of the pores was observed on the milled surfaces. The chips of the porous material show a disrupted surface. In future investigations, the aim is to improve the wear behaviour when milling porous Inconel 718.