Preparing porous diamond composites via electrophoretic deposition of diamond particles on foam nickel substrate

Highlight
• Porous diamond composites were successfully prepared via EPD.
• Foam nickel was used as porous substrate.
• Uniform and fully-covered diamond coatings were obtained at 6 V/cm for 20 min.
• Porous composites were turned out to have great mechanical properties.

Porous diamond composites with excellent mechanical properties were successfully prepared using foam nickel as substrate. Diamond particles with the size of 1–2 μm were electrophoretic deposited on foam nickel, followed by electroless nickel plating on the diamond-coated foam nickel to enhance the adhesion between diamond particles and the foam nickel substrate. The optimum electric field intensity was explored and determined to be 6 V/cm. Field emission scanning electron microscope was employed to investigate the morphologies of diamond coatings with different electrophoretic time and Ni-diamond composite coatings after electroless plating. The results showed that the diamond deposits increased with the electrophoresis time extended, while uniform and fully-covered diamond coatings were formed after 20 min deposition. Besides, diamond particles were held tightly by Ni coatings which played the role of metal bond. The bending strength of the porous composites was about 100 MPa determined by three-point bending test, and the composites were turned out to be suitable for grinding.