Tribological properties of low-temperature graphite fluorides. Influence of the structure on the lubricating performances

Abstract

International audienceThe present work is concerned with the study of the tribological properties of various fluorinated carbon phases obtained at room temperature and then post-treated under fluorine atmosphere at different temperatures. The tribological tests evidence good intrinsic properties for all the compounds (friction coefficient in the range 0.07-0.09). Differences appear after few cycles. Friction measurements after 100 cycles and complementary Raman analyses of the tribofilm remaining in the wear scar point out that long term tribologic properties of the fluorinated compounds strongly depend on the evolution undergone by the materials under friction. The release of HF molecules, the loss of fluorine and partial rebuilding of graphitic phases are at the origin of the degradation of the friction properties. The good properties of the compounds post-treated at temperature in the range 150-300 °C are attributed to the chemical and structural stability of these compounds under friction

Tribological Properties of Fluorinated Carbon Nanofibres

“…5), the D peak at 1348 cm -1 and a composite one centred at 1612 cm -1 , this last peak resulting due to the G and D' overlap. As previously mentioned in the literature [10], the I D /I G intensity ratio increases as a function of disorder in the carbon material. The I D /I G ratios in the initial CNFs and in the tribofilm are, respectively, 0.4 and 1.7 pointing out a drastic increase of disorder corresponding to the transformation of part of the initial CNFs into ill-organized carbon material in the final tribofilm during the friction process.…”

“…These compounds present good lubrication properties as the obtained friction coefficients are similar to those of conventional graphite fluorides. We showed that several parameters such as the nature of the C-F bonds, the presence and the nature of intercalated species and the fluorine content strongly influence the tribological properties of the fluorinated phases [10].…”

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

“…The coexistence of sp 2 and sp 3 carbon atoms confers to these materials interesting electrochemical properties for primary lithium batteries [16]. We showed in a previous work that the compounds obtained in the case of F 2 , HF, and IF 5 mixture present rather good tribologic properties, influenced by the nature of the C-F bonds, the presence of intercalated species and the fluorine content [17].…”

Superlubricity in Layered Nanostructures

“…Recently synthesized CF [16] is similar to CH, but F atoms are negatively charged. Tribological properties of carbon based fluorinated structures have been the focus of interest [23,24]. In the layers of MoS 2 or WO 2 , the plane of positively charged transition metal atoms is sandwiched between two negatively charged outer S or O atomic planes.…”