Laboratory Evaluation of Lubricants for Cold Rolling Aluminum Alloys

An instrumented laboratory rolling mill was used to obtain data on the performance of five mineral oil base lubricants in rolling 1100 and 5182 aluminum alloys in the annealed and partially hard tempers. The maximum reductions in a single pass were determined for each lubricant with these alloys. An analysis of the data indicated that the best criterion of the frictional aspects of the lubricants during rolling was the energy used to overcome friction when it was plotted against a Sommerfeld number which used the constrained yield stress of the strip as pressure, the differences in roll and exiting metal velocities as speed, and a viscosity adjusted for the temperature and pressures estimated to exist in the lubricant film during rolling. The correlation of this kind of performance with the known production mill performance of these lubricants was very good. Coefficients of friction calculated from these rolling data did not correlate with known mill performance.