Comparative study of the effects of nano‐sized and micro‐sized CF and PTFE on the thermal and tribological properties of PEEK composites

Abstract

The tribological characteristics of PEEK composites fretting against GCr 15 steel were investigated by a SRV-IV oscillating reciprocating ball-on-disk tribometer. In order to clarify the effect of type and size of fillers on the properties of PEEK composites, nano-sized and micro-sized CF and PTFE fillers were added to the PEEK matrix. The thermal conductivity, hardness, and fretting wear properties of PEEK composites reinforced by CF or PTFE were comparatively studied. The results showed that the type and size of the fillers have an important effect on both the friction coefficient and wear rate, by affecting their thermal conductivity, hardness, as well as the surface areas of their transfer films. In comparison, the effect on improving the tribological properties of micro-sized CF was superior to that of nano-sized CF, while the effect of nano-sized PTFE was superior to that of micro-sized PTFE. Considering the acceptable friction coefficient and wear rate of the composite under the fretting wear test, it seemed that 4% nCF, 20% mCF, 2% nPTFE and 10% mPTFE were desired additive proportions. And it also can be found that during the fretting wear test, the abrasive and adhesive wear resulted in accumulative debris at the contacting surface. The transfer films made of debris were formed on the counterfaces.

Influence of cenosphere on tribological properties of short carbon fiber reinforced PEEK composites

“…However, a lower friction coefficient was obtained with the increase of load for PEEK/SCF and PEEK/SCF/CS composites, which may be due to the good thermal conductivity of carbon fiber and cenosphere. Carbon fiber or cenosphere can help conduct heat of the frictional contact surface in time, the surface temperature is relative lower compared with PEEK, then there is no serious adhesive wear (see Figure ) of PEEK composites under high load . Here, in this case, the former of the two competitive actions takes over the dominant position.…”

Effect of SiO2 nanoparticles‐decorated SCF on mechanical and tribological properties of cenosphere/SCF/PEEK composites

“…The reason is that the shear strength of pure PEEK resin decreases under high load, and serious adhesion wear occurs on the surface during friction, which increases the friction coefficient. For CS/SCF/PEEK and CS/SCF‐SiO 2 /PEEK composites, a positive rolling effect of micrometer‐sized CS and nano‐SiO 2 particles between the material pairs reduced the stress concentration on the fibers, while SCF could reduce the friction heat on the wear surface to avoid the phenomenon of severe adhesion . Eventually, the friction coefficient was reduced.…”

The effect of different layered materials on the tribological properties of PTFE composites

“…However, the poor mechanical properties and high wear rate of PTFE have limited its application in the abovementioned fields [4][5][6]. To reduce the wear rate and exploit the advantages of PTFE, researchers have found that load-carrying capability and wear resistance can be improved by filling the PTFE matrix with various fillers such as organic and inorganic fibers [7,8], and nano-and microscaled particles [9,10]. For example, Burris and Sawyer reported improvement in anti-wear properties by up to four-orders of magnitude by incorporating nano-Al 2 O 3 into PTFE [11].…”