The role of rolling lubrication cleanliness on the surface quality of cold rolled aluminum sheets

A series of on line particle size measurements was made by taking the effect of filter medias, filter time, rolling speed as well as the thickness and the composition of the sheets rolled into account to monitor the filter efficiency during rolling. The cleanliness of sheets rolled was measured and Scanning Electron Microscopy was used to see the surface of the sheets. The compositions and rates of base oil and additive oils were held constant. The ratio of DE/BE as well as precoat thickness were effective parameters on particle sizes and numbers observed in the lubricant filtered. Higher ratio of DE/BE and 2 mm precoat thickness gave an improved filter performance. There were interactions among diatomaceous earth type, DE/BE ratio and precoat thickness in consideration of filter performance. Aluminum fines gathered from the surfaces of sheets could give an idea on wear mechanism and its rate. The sizes and the number of particles were greater in thick sheets than that of thin sheets. This is an abstract of a paper presented in the 2005 STLE 60th Annual Meeting (Las Vegas, NV 5/15-19/2005).