Thermo-optical-measurement technique TOM to characterize sintering behavior of additive manufactured metallic parts under atmospheric control
Following the shrinkage of powder metallurgical samples of unusual shape is possible employing our thermo-optical measurement device with atmospheric control (TOM-AC). Its accuracy of better than 0.5 microns resolution reached during contact-less measurements and its robust contour-detection algorithm allow a data quality making a numerical derivative of the shrinkage possible. Hence, we present here shrinkage and shrinkage rates for spheres of carbonyl iron, metallic foams and a grid produced by screen printing of stainless steel powder. The TOM-AC allows not only measuring samples of arbitrary shapes but also changing the sintering atmospheres (vacuum, inert gas or reducing gases like hydrogen mixtures) during the heat treatment at chosen temperatures. The whole control during the heat treatment is realised via a specific code on a standard PC.