Mechanical and Microstructure Characterization of Binder Jetting Additive Manufacturing of 17-4PH Stainless Steel

Abstract

The present work provides insights into the Binder Jet Additive Manufacturing (BJAM) process parameters that influence the material properties such as porosity, and mechanical properties of the 17-4PH stainless steel parts. The number of specimens was 27, in which a layer thickness, drying time, and saturation of a binder were selected as process variables. Porosity of the BJAM specimens is in the range of 1.96%-3.95%, Low porosity was achieved with thinner layers, longer drying times, and higher binder saturations. The observed maximum microhardness of heat-treated specimens was 48 HRC at the given parameters, but 51 HRC was found for the material whose morphology was wrought. From the results related to tensile properties, it is concluded that thinner layers and higher binder saturation lead to better Ultimate Tensile Strength (UTS) and Yield Strength (YS). Elongation, which characterizes the ductility of materials, was dependent on the density and process efficiency enhancement that were carried out. Parts produced by the BJAM process yielded fracture patterns that can be described as ductile-brittle mixed mode fractures.