Using a horizontal reciprocating friction and wear test apparatus, this study evaluated the effects of PTFE particle composite and electrolysis conditions on friction and wear properties of AZ91D magnesium alloy treated with anodization from a phosphate and ammonium electrolytic solution against the SUJ2 steel ball. Wear loss of the AZ91D magnesium alloy anodized from the phosphate and ammonium solution was greatly reduced in comparison with no surface treatment, but the alloy's friction coefficient was high. The PTFE particle composite used as the coating was produced to lower the friction coefficient in the early stage of testing. Moreover, the coating was smoothed and hardened using AC electrolysis to lower the friction coefficient.
Because of its superior tribology and hardness properties, DLC film is applied to cutting tools and mechanical sliding components. However, when the film is applied to a Parts carrier system for semiconductors, wear resistance of the film is necessary to maintain the positioning accuracy and to avoid yielding of wear-dust. Furthermore, electrical conductivity of the film is necessary to eliminate the dust adsorption that results from electrification by static electricity, which occurs because of the friction between Parts and the carrier system. Although nitrogen or boron doping is known to be effective to raise the film conductivity, the effect of boron on mechanical characteristics has not been elucidated yet. This study examines electrical and mechanical properties of boron-doped DLC film synthesized using RF plasma CVD method. Results show that boron doping of more than 1% decreases the film electrical resistance from 1010 Ωcm to 102 Ωcm, whereas the increase of the element decreases hardness. A ball on disc wear test of the film revealed that the friction coefficient is around 0.2, irrespective of boron content, at 373.15 K.
In this study, diamond-like carbon(DLC)films are modified using O2 and CF4 plasma generates by radio frequency(RF), taking into account surface wetting and tribological properties. Surface properties of O2 and CF4 plasma-treated DLC are characterized using atomic force microscopy(AFM), Attenuated total reflectance-Fourier transform infrared(ATR-FTIR)spectroscopy, ball-on-disk friction testing, and contact angle measurements. The results indicate that hydroxyl group generates on the surface of the O2 plasma-treated DLC with surface roughness of approximately 0.20-0.25 nm, while fluorinated group also generates on the surface of the CF4 plasma-treated DLC with surface roughness of approximately 0.16-0.21 nm. The O2 plasma-treated DLC films present hydrophilic surfaces due to their low contact angles and high surface energies. In contrast, CF4 plasma-treated DLC show hydrophobic surfaces, as evidence by their high contact angles and low surface energies. Further, CF4 plasma-treated DLC film surfaces exhibit friction coefficients as low as untreated DLC, but O2 plasma-treated DLC exhibit higher friction coefficients than that of the untreated DLC. It is concluded that CF4 plasma treatment can be used to produce hydrophobic DLC, making DLC a favorable non-wetting surface and improving its friction coefficient.
We investigated the friction coefficient in electroless Ni-P/SiC composite plating films. From results of this study, which revealed that the coefficient can be maintained low by heat treatment, we infer that SiC co-deposited in the composite films inhibits film embrittlement.