Deformation-free Functional Gradient ZrO2/Ni Fabricated by Shrinkage-matched Materials Extrusion 3D Printing

Ceramic/metal functional gradient materials (FGMs) are used in a wide range of applications in energy, machinery, aerospace and other fields due to the advantages of both ceramic and metal materials. However, conventional laser additive manufacturing faces significant challenges, such as consequential residual thermal stresses due to the large physical differences between ceramics and metals, which lead to warpage deformation and interlayer cracking of the material. Therefore, this paper introduces a new strategy to prepare ZrO 2 /Ni FGMs based on shrinkage-matched materials extrusion 3D printing. Firstly, the consistency of shrinkage of ZrO 2 and Ni was achieved with a minor volumetric shrinkage different of 0.6% by adjusting the solid content of the slurry and the sintering temperature. Then, the microstructure and mechanical properties of FGMs with different numbers of gradient layers (2, 3, 5) and thicknesses (100   µm, 150   µm, 200   µm) were investigated, demonstrating a gradual elemental and mechanical gradient. Through the analysis of fracture cracks and fracture surface morphology, the fracture process and mechanisms of the samples were elucidated. Finally, several typical structures FGMs were prepared from pure metal to pure ceramic in both XY and Z directional gradient. Overall, it addresses the challenges associated with fabricating deformation-free ceramic/metal FGMs and developing strong bonds between ceramics and metals.