Effect of phosphorus content on mechanical properties of polymeric nickel composite materials with a diamond-structure microlattice

Periodical and ordered polymer-nickel-coated composite materials with a diamond-structure microlattice and various contents of phosphorus (4.10 wt%, 8.01 wt%, 12.25 wt%, 16.08 wt%, 20.21 wt%) were fabricated via electroless nickel-phosphorus (Ni-P) coating onto diamond-structured polymeric templates using a 3D printing stereo lithography apparatus. With the increase in P content, the crystal morphology transfers from crystal to non-crystal. By controlling identical 1.0 μm-thickness of 5 different content coatings onto templates, the properties of 5 different microlattice composites were tested by uniaxial compression. To confirm the thickness and P content, several mathematical models were developed to direct the subsequent experiments and all theoretical predictions are in agreement with factual characterization. The composite with 8.01 wt% phosphorus content and density of 240.4 kg m⁻³ performs best, with the maximum compressive strength reaches 1.08 MPa, which is 2.1 times higher than that of polymer templates.