Experimental investigation and modeling of densification during sintering of binder jetted Ti–6Al–4V

Abstract

Binder-jetted parts require a subsequent sintering process to achieve the desired density and mechanical properties, resulting in anisotropic shrinkage and creep distortion. To compensate for this, accurate prediction of densification behavior is required. Although there has been research on optimizing the printing and sintering process to increase the reproducibility of Ti–6Al–4V parts, there is no accessible literature on modeling the densification behavior. In this study, the densification of binder-jetted Ti–6Al–4V samples is investigated experimentally through experiments with interrupted sintering cycles and dilatometry. Through these experiments, it is possible to determine the density changes throughout the entire sintering cycle as well as the anisotropic shrinkage of the printed samples. The results are used to calibrate phenomenological diffusion models for intermediate stage and final stage sintering capable of mapping the densification behavior throughout the entire sintering process. Due to experimental limitations, material parameters for grain growth are determined from experimental densification data.