Tribological Properties of Room Temperature Fluorinated Graphite Heat-Treated Under Fluorine Atmosphere

Abstract

This work is concerned with the study of the tribologic properties of room temperature fluorinated graphite heat-treated under fluorine atmosphere. The fluorinated compounds all present good intrinsic friction properties (friction coefficient in the range 0.05-0.09). The tribologic performances are optimized if the materials present remaining graphitic domains (influenced by the presence of intercalated fluorinated species) whereas the perfluorinated compounds, where the fluorocarbon layers are corrugated (armchair configuration of the saturated carbon rings) present higher friction coefficients. Raman analyses reveal that the friction process induces severe changes in the materials structure especially the partial rebuilding of graphitic domains in the case of perfluorinated compounds which explains the improvement of l during the friction tests for these last materials.

Friction Properties of Fluorinated Carbon Nanodiscs and Nanocones

“…5 shows a reduction of the graphitic domains size (L a and L c ) as a function of the F/C ratio down to an asymptotic value close to 7 ± 2 nm in agreement with previous works [29,30,41]. The main structure results deduced from these analyses on initial compounds and fluorinated derivatives are schematically synthesized in Fig.…”

“…In the case of CND2700s, the influence of the fluorine content is weaker. As for graphite fluorides [29,41], the best tribologic performances (l \ 0.08) are obtained for F/C ratios in the range 0.1-0.7, the friction coefficients for F/C [ 0.7 being larger than the initial compound one. Figure 7 shows that the friction coefficients are similar for CNDs and CND2700s for fluorine contents close to the unity (l CNDs & l CND2700s & 0.1).…”

New synthesis methods for fluorinated carbon nanofibres and applications

“…The obtained friction coefficients, close to 0.08, are nearly similar to CNFs fluorinated using F 2 gas when the F/C molar ratio is above 0.15 [30]. Such friction coefficient values are as low as those of conventional fluorocarbon lubricants [3,[31][32][33]. For example, the friction coefficients of graphite fluoride (CF) n with CF 1.12 composition is ranged in between 0.03 and 0.15 over the 25-250 8C temperature range.…”

“…For example, the friction coefficients of graphite fluoride (CF) n with CF 1.12 composition is ranged in between 0.03 and 0.15 over the 25-250 8C temperature range. Low friction coefficients, over 0.055-0.07 range and stable upon cycling, have been obtained using graphite fluoride prepared at low temperature by F 2 /HF/IF 5 catalytic gaseous mixture treatment followed by post-treatment under fluorine gas at 300 8C [33]. For such compounds the optimization of the tribologic properties is related to the partial conservation of the planar shape of graphene planes.…”

Tribological properties of fluorinated nanocarbons with different shape factors

“…In the present work two strategies are investigated to improve the tribological properties of nanocarbon phases [11][12][13]:…”