Analysis of the Flatness Form Error in Binder Jetting Process as Affected by the Inclination Angle

Binder jetting (BJ) has demonstrated high competitiveness among additive manufacturing processes on account of its high production rate at a low material cost. However, both the design procedure and the process for BJ have to be further developed, aiming towards the proper control of the geometrical and dimensional precision and accuracy of the final product. This paper aims to study the factors that affect the flatness form error. Five geometries were designed to obtain planes that were inclined with respect to the fabrication direction. These planes were measured by a coordinate measuring machine in both the green and sintered state, deriving the best-fitting plane and the flatness form error. The analysis of the green samples demonstrates the prevailing influence of saturation level and layer shifting on flatness form error. In the sintered parts, a dimensional change in sintering can determine shape distortion, or an increment in the surface irregularity observed in the green state. The experimental results clearly evidence the effect of both printing and sintering on the quality of the final product, which should be considered when designing parts to be produced using BJ technology.