Abstract
The high velocity oxy-fuel (HVOF) combustion spray process has previously been shown to be a successful method for depositing pure polymer and polymer/ceramic composite coatings. Polymer and polymer-ceramic composite particles have high melt viscosities and require the high kinetic energy of HVOF in order to generate sufficient particle flow and deformation on impact. One of the goals of reinforcing polymer coatings with particulate ceramics is to improve their durability and wear performance. Composite coatings were produced by ball-milling 60 µm Nylon-11 together with nominal 10 vol.% of nano and multi-scale ceramic reinforcements and HVOF spraying these composite feedstocks onto steel substrates to produce semi-crystalline micron and nano-scale reinforced coatings of polymer matrix composites. The room temperature dry sliding wear performance of pure Nylon-11, Nylon-11 reinforced with 7 nm silica, and multi-scale Nylon-11/silica composite coatings incorporating 7 to 40 nm and 10 µm ceramic particles was determined and compared. Coatings were sprayed onto steel substrates, and their sliding wear performance determined using a pin-on-disk tribometer. Coefficient of friction was recorded and wear rate determined as a function of applied load and coating composition. Surface profilometry and scanning electron microscopy were used to characterize and analyze the coatings and wear scars.
