Influence of LPBF Parameters and Strategies on Fine Machining of Pre-Built Bores

Abstract

Additive manufacturing changes the classical possibilities of production. However, post-processing is usually unavoidable for these components to achieve functional performance. To obtain an optimum product, knowledge of the characteristics of the additive manufactured part and the machining mechanisms depending on these characteristics is required. In this paper, the influence and the interaction of the laser powder bed fusion process parameters on the subtractive post-processing are shown. The effects of the parameters on the geometry of bores are examined and subsequently the precision machinability is analysed using reaming. In addition, a process simulation is carried out to correlate the simulated deformation to the required machining allowance for subsequent reaming. The aim of this investigation is to examine the capabilities of the laser powder bed fusion process to produce bores at angles of 90° (vertical), 60° and 45° that can be machined directly with a reaming tool without the need for drilling.

The Additive-Subtractive Process Chain - a Review

“…Recent work has shown that there are correlations between the scanning strategy during the AM process, the process planning and parameterisation in mechanical machining and the resulting machinability as well as the component properties produced [197], which can be attributed to the respective influence of the material microstructure. The direction of build-up in the AM process and the relative direction of machining, the respective process parameters and heat treatment conditions have a decisive effect on the surface properties of the components [198,199]. Properties such as the fatigue, wear and corrosion behaviour of the components are significantly influenced by the interactions of the individual process steps [200].…”