The role of block-type support structure design on the thermal field and deformation in components fabricated by Laser Powder Bed Fusion

Abstract

Successful production of overhang features, with no underlying deposited layers or substrate, in a Laser Powder Bed Fusion (LPBF) process requires sacrificial structures, known as support structures. However, these structures add extra time and cost to the manufacturing process of a component. Optimisation of support structure design should reduce materials waste (which affects the time and cost of the build process) while minimising bleed-throughs and residual deformation. Optimisation of support structure design requires an understanding of their impact on the thermal field and mechanical constraints. In this research, a combination of experiments and numerical modelling was used to quantify the contribution of various support structure design elements on component deformation. The results indicate that the total contact area of teeth and the total support base area alter thermal fields within the produced components. Increasing the area for heat conduction to the start plate was found to reduce the peak temperature in the cantilevered plate. Additionally, increasing the contact area between teeth and the cantilevered plate reduces the peak temperature and the vertical temperature gradient in the overhang platform, both of which are consistent with reducing in-situ plastic strain accumulation and residual part deformation.