Modeling of effect of powder spreading on green body dimensional accuracy in additive manufacturing by binder jetting
A. Maximenko, I.D. Olumor, A.P. Maidaniuk, Eugene A. Olevsky
Abstract
It is shown that Bullet Physics Engine can be used for Discrete Element modeling of powder spreading during additive manufacturing by binder jetting. It is known that, due to technological restrictions, the thickness of deposited layers during binder jetting should not exceed several powder particle diameters making the application of continuum models of powder medium behavior to be problematic. Discrete element modeling provides the detailed information on powder behavior during powder spreading. The conducted modeling shows that dilation of the deposited powder and distortion of previously deposited layers depend on the amount of powder that is removed during spreading, on the thicknesses of the deposited layers, and on the dimensions of the manufactured components. An empirical equation describing the distortion strain as a function of powder spreading parameters is suggested as an approximation of the numerical modeling results. The main trends in green body distortion under powder spreading are experimentally validated.