Three-dimensional printing (3DP™
1
) is a layer-by-layer manufacturing process whereby a
three-dimensional (3D) component is created by the distribution of a liquid binder onto a powder
media. A 3DP™ process using stainless steel powder as its printing media requires post-printing
thermal processing for debinding and sintering of the printed green component. To minimize
dimensional distortion while increasing structural integrity of the green component, 3DP™
thermal post-processing is designed to produce only neck growth between particles, defined as
initial stage sintering.
The accepted theoretical model governing initial stage sintering strain for spherical powder
particles provides a qualitative account of strain development with respect to time and
temperature variance; however, the model does not produce an accurate quantitative account for
the magnitude of the strain when compared to dimensional experimental results. The theoretical
model indicates that powder particle size is the dominant parameter governing sintering strain.
The purpose of this study is to introduce an effective particle size into the theoretical model,
thus enabling the application of the theoretical model to estimate dimensional change for
components produced by 3DP™. Dimensional sintering experimentation has been performed
using 3DP™ test specimens with spherical powder particles having mean diameters of 20 Pm, 80
Pm, and 200 Pm. Experimental results and progress on the theoretical model are discussed.Financial support for this work is provided by the Office of Naval Research, Contract
#N00014-C-00-0378.Mechanical Engineerin
