Influence of Sticking on the Roll Topography at Twin-Roll Casting of Aluminum Alloys

The formation of strips at twin-roll casting depends on the state of the roll surface. The processing conditions, which are characterized by high metal-tool interface temperatures and compression stresses, provoke sticking between the cast material and the rolls. This effects changing of the tool’s topography, impairment of the strip’s surface quality and interference of its flatness. In the scope of this study the evolution of roll’s topography at twin-roll casting of 3 mm thick strips of aluminum alloys EN AW-1070 and EN AW-6082 without any release agents was experimentally analyzed using laboratory casting unit. The effect of repetitive tool’s self-cleaning during processing of the EN AW-6082 alloy was observed, whereas aluminum of technical purity showed intensive sticking on the roll surface. In the last case micro-profiling of the tool’s surface is not more efficient and release agents have to be used for improvement of the strip’s formation conditions.