PEEK is a high strength engineering thermoplastic that suffers from a high friction coefficient and a friction induced wear mode. Past studies with 0 m PEEK and PTFE powders resulted in composite solid lubricant that (at the optimal composition) had a wear rate of k= 2× 10−9 mm3/Nm ith a friction coefficient of μ= 0.12. A compositional grading of PEEK and PTFE is implemented in this study to cr...

--The lubricating properties of commercially available mucins originating from different animal organs, namely bovine submaxillary mucin (BSM) and porcine gastric mucin (PGM), have been characterized at polymeric surfaces for biomedical applications. Atomic force microscopy (AFM) and pin-on-disk tribometry have been employed for tribological studies at nanoscale and macroscale contacts, respect...

This work explores the effect of surface modification of stainless steel with a carbon nitride (CNx) film, under sliding wear of the UHMWPE/steel. Wettatibility of CNx coatings is assessed by means of the sessile drop method using two different liquid media. Microhardness and stiffness of CNx coatings are estimated by depth-sensing indentation. The sliding performance of UHMWPE against stainles...

A simple, but not widely known, mathematical fact concerning the coverings of the full Lorentz group sheds light on parity and time reversal transformations of fermions. Whereas there is, up to an isomorphism, only one Spin group which double covers the orientation preserving Lorentz group, there are two essentially different groups, called Pin groups, which cover the full Lorentz group. Pin(1,...

in the past 30 years, electroless nickel (en) plating has grown to such proportions that these coatingsand their applications are now found underground, in outer space, and in a myriad of areas inbetween. moreover, in order to further improve the mechanical and tribological properties of thenickel-phosphorous (ni-p) coatings, ni-p/ptfe composite coatings can be obtained, which provideseven grea...

In industrial chain drives, the sleeve slides on pin and impact loading occurs due to polygon effect, while collision between ball cage usually produces an impact-sliding motion in rolling element bearings. Aiming at addressing occurrence of surface damage caused by motion, a ball–disk test rig employing optical interference technology was designed built realize load variation. Two kinds commer...