The microstructure and mechanical properties of nickel fabricated by material extrusion-based 3D printing

This study presents a fabrication method for preparing Ni using material extrusion-based 3D printing. First, the corresponding printing process window was optimized by exploring the relationship between the layer thickness and printing parameters (printing air pressure, printing speed, and printing height) of different solid content slurries, slurries rheology, and platform heating temperature. Then, the experiments on Ni slurries with different solid contents under different post-treatment methods were investigated to obtain the effect of solid content and temperature on the material properties. The results show that when the solid content of Ni slurry increases from 70 to 84 wt. %, the relative density of Ni increases, the shrinkage decreases, and the mechanical properties increase; when the sintering temperature increases from 1250 to 1400 °C, the relative density of Ni increases, the shrinkage increases, the mechanical properties decrease, and the particle size increases. The relative density range is 82%–96.6%, the shrinkage range is 53.5%–59.6%, the tensile strength range is 237.7–294 MPa, and the hardness range is 51.6–104.8 HV. Finally, the relationship between slurry, manufacturing process, structure, and properties was established through process optimization and experimental results, and 3D models of different structures were prepared to complete the preparation of Ni with high structural integrity, good interlayer bonding, and excellent properties.