Electroforming of Ni-P-PTFE Nanocomposites with Nanoscale Surface Roughness and Superior Self-Lubricating Properties

The electrodeposition of Ni-P-PTFE nanocomposites offers an effective approach to reduce mold-polymer interface adhesion and improve the replication of polymer micro features in injection molding. However, it is still challenging to fabricate Ni-P-PTFE nanocomposites with low internal stress and nanoscale surface roughness in electrolytes containing high PTFE concentrations. In this study, cetyltrimethylammonium bromide was introduced into the electrolytes to achieve a good dispersion of PTFE nanoparticles. Ni-P-PTFE nanocomposites with various compositions were successfully electrodeposited, and their tribological properties were analyzed. The electroformed Ni-P-PTFE nanocomposites with high PTFE and phosphorus contents showed a low surface roughness and surface energy compared to nickel electrodeposits. Ni-P-PTFE nanocomposites also exhibited a low coefficient of friction (COF) and wear loss when electroformed from an electrolyte containing 32 g/L phosphorus acid and 5 g/L PTFE nanoparticle. The COF of Ni-P-PTFE against stainless steel and poly(methyl methacrylate) was 0.2 and 0.12, respectively, representing a decrease of 80% and 85% compared to nickel electrodeposits. These enhancements in self-lubricating performances were primarily attributed to the low surface roughness and a shift in wear modes from adhesive wear to predominantly mild abrasive wear.