Process for obtaining multilayer materials suitable for transformation into hollow bodies by drawing or drawing and ironing

摘要

A process for obtaining a multilayer material suitable for transformation by drawing or drawing and ironing into a hollow body having a height to diameter ratio greater than 2.5. The process comprises subjecting an aluminum alloy substrate to an anodizing or chemical conversion surface treatment for improving adherence thereto, covering one of the surfaces of the substrate by adhering a plastic material film thereto, and covering the other of the surfaces with a coating of varnish including a solid lubricant in the form of particles which are harder than the varnish. The coated substrate is subsequently drawn or drawn and ironed into a hollow body utilizing tools having a hardness which is greater than the particles.