Material extrusion of stainless-steel plate-lattice structure: Part shrinkage, microstructure, and mechanical performance

Abstract

Additive manufacturing (AM) has been rapidly developed to fabricate metal lattice components owing to its capability in building complex geometries. However, the prevalent powder bed fusion-based technologies possess low manufacturing efficiency and high energy consumption that encumber their broad adoption. Here in this study, a cost-effective material extrusion-debinding-sintering technology using a commercial AM system was introduced to produce 17-4 PH stainless steel plate-lattice structures. Three types of plate-lattice structures were successfully fabricated in a minimum dimension of 0.4 mm. The anisotropic shrinkage of the plate-lattices has been calculated by measuring the dimensions of green, brown and final sintered parts in both top and side views. The body-centered cubic (BCC) plate-lattice exhibited equiaxed grains with an average grain size of 12.7 µm, and a few carbides were distributed on the surface. A compression test has been conducted to reveal the compressive stiffness and yield strength. Both BCC and face-centered cubic (FCC) plate-lattices exhibited higher stiffness than BCC-FCC type, and the FCC plate-lattice has the highest yield strength under compressive load. The FCC and BCC-FCC structures possessed higher ductility than BCC type due to the even deformation at the post-yield region. The successfully built metal plate-lattice structure evidences the great potential and possibility of material extrusion in fabricating low-cost metal components for a variety of industrial applications.