Date of Graduation
Bachelor of Science in Mechanical Engineering
Mechanical components with lower coefficients of friction decrease the amount of energy dissipated by the system due to friction. Coating these components would decrease the coefficients of friction between surfaces without sacrificing the strength of the components. A polytetrafluoroethylene (PTFE) layer adhered through a polydopamine (PDA) layer on a steel substrate will reduce the coefficient of friction on the substrate surface. This paper discusses different methods for attempting to increase the uniformity of the PDA layer as well as decrease the PDA coating time. Methods for increasing uniformity include using a particle disperser instead of a magnet stir rod, changing the orientation of the coating surface in the solution, and changing the position of the coating surface in the solution. The PDA deposition time was decreased by increasing the temperature of the PDA solution. After applying the PDA layer onto the steel substrate, a PTFE layer was applied to the steel substrate by dipcoating. The different samples were tested for coefficient of friction and durability cycles. The method for the most uniform PDA distribution as well as highest durability of PDA/PTFE coating was the steel substrate that was in PDA solution at 90°C mixed with a particle disperser spinning at 2800 rpm for 6 hours. This sample yielded an average coefficient of friction of 0.0950 and lasting and average of 512 cycles under a 15 N normal load.
Jenkins, Samuel L., "Polytetraflouroethylene Thin Coatings For Tribological Applications" (2016). Mechanical Engineering Undergraduate Honors Theses. 51.