INVESTIGATION OF STATIC FRICTION BETWEEN RUBBER AND MODIFIED ALUMINUM SURFACES PRIOR TO VULCANISATION

This study takes into account static friction as a pre-tool in assessments of metallic surfaces before bonding with rubber in automotive applications. In this work, aluminum alloy samples were peened and blasted to generate rough surfaces by glass shots and ferrous grits, separately. Surface roughness of the aluminum samples was previously measured. Afterwards, the static friction behaviours of the untreated and modified aluminum surfaces on the rubber plane were investigated under dry sliding. In conclusion, the surface roughness remarkably increased with short exposure times up to 15 min. The roughness values were unstable at the longer exposure times. The incremental surface roughness was related with the coefficient of friction in the short exposure times, but not long processing duration of the roughed aluminum surfaces. From all the smooth and rough aluminum surfaces, the lower and upper limitations of the coefficients of friction were statistically determined as 0.80 and 1.58, respectively. The static friction experiments indicated that the increase in coefficients of friction at the metal-rubber contact could be associated with a stronger interface adhesion. In association with the coefficients of friction for the aluminum-rubber couple, the measurement of the static friction could be a better method than the in-line roughness measurement in assessments of metallic surfaces prior to the interface vulcanisation.