Macro-scale friction coefficient

Miyata and Yamaoka [26] used scanning probe microscopy (SPM) to determine the micro-scale friction force of a silicone-treated polymer film surface. PU acrylates cured by an electron beam were used as the polymer films. The micro-scale friction force obtained by SPM was compared with macro-scale data, such as surface free energy determined by the Owens-Wendt method and the macro-scale friction coefficient determined by the ASTM D1894 method [27]. These comparisons showed that a good linear relationship existed between the surface free energy and the friction force, which was insensitive to the nature of the polymer specimens or to the silicone... 

The main results in the current study is that ju of the CoCr femoral head for the lubricants of PBS, BSA of 10 mg/ml, and BSA of 30 mg/ml were 0.248 0.029, 0.195 0.014, and 0.073+0.014, respectively. In the literature, AFM measurements with different lubricants of the frictional coefficients on the surface of a CoCr femoral head have not been reported. Regarding the macro-scale frictional coefficients of a CoCr alloy with lubricants through pin-on-disk measurements, Mishina et al. have reported that /Li between CoCr and CoCr with human seram albumin (HSA) was -0.08 [11], while Gispert et al. have reported that ji between CoCr and UHMWPE with Hank s balanced salt solution (HBSS) was -0.24 [10], Jin et al. have also reported that fx between CoCr and UHMWPE through hip simulator with the lubricant of BSA solution lie between 0.06 and 0.08 [5]. 

Therefore, for a rough surface, although it is smooth macro-scopically, the friction coefficient is greatly affected by its surface morphology. For a smooth surface on atomic scale, 0 can be neglected and the friction coefficient is only related to the twist angle of the cantilever. 

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