Morphological and physical properties and friction/wear behavior of h-BN filled PEEK composite coatings

• Wear and friction coefficient of PEEK coatings prepared by flame spraying process decreased with the adding h-BN particles.
• h-BN content had a greater effect on the unmelted PEEK and surface roughness whereas the particle size of h-BN did not.
• The self-lubricant property and the appearance of h-BN network structure in PEEK coating decreased the friction and wear.
• The self-lubricant property and the appearance of network structure of h-BN in PEEK coating decreased the friction coefficient and specific wear rate.

Hexagonal boron nitride (h-BN) powder with different particle sizes and contents was incorporated in polyether ether ketone (PEEK) under ultrasonic conditions and deposited using flame-spray coating technique. Specific wear rate and friction coefficient of the h-BN/PEEK composite coatings were determined using a ball-on-disk sliding wear tester under applied loads of 5–25 N. Microstructure, microhardness, degree of crystallinity and surface roughness of the h-BN/PEEK composite coatings were investigated. The results showed that the microhardness and degree of crystallinity could be improved with h-BN particles. At an applied load of 5 N, the addition of h-BN particles into PEEK gave a lower specific wear rate. A higher content of h-BN added to PEEK coating resulted in a decrease in the friction coefficient. At an applied load of 25 N, 8 wt.% h-BN/PEEK composite coatings provided good friction reduction while the composite coatings formed severe wear with grooves.