Method for producing components for motor-vehicle structures, having a hybrid structure made of light alloy and plastic material

A method for obtaining a component of a motor-vehicle structure by a hot pressing operation on at least one sheet element of light alloy, said method comprising the steps of:

• providing a hybrid panel adjacent to a mould element having a forming surface,
• wherein said hybrid panel comprises at least one sheet of plastic material in contact with said at least one sheet element of light alloy substantially along an entire extension thereof, so that said hybrid panel has at least one layer of light alloy sheet and one layer of plastic material,
• hot forming said hybrid panel in its entirety by pressing it against said forming surface of said mould element with a predetermined controlled pressure and by simultaneously applying heat, until the hybrid panel assumes a configuration corresponding to that of said forming surface,
• wherein preliminarily to the hot forming step of the hybrid panel, a surface of said at least one sheet element of light alloy which is to come in contact with the at least one sheet of plastic material is subjected to a roughening treatment, so as to define surface asperities,
• wherein before said hot forming step said at least one sheet element of light alloy and said at least one sheet of plastic material are coupled with each other so as to be in contact substantially along their entire extension, in a loose condition, without any preliminary mutual connection, and
• wherein said at least one sheet element of light alloy and said at least one sheet of plastic material constituting the hybrid panel are caused to adhere to each other following softening by heat of the at least one sheet of plastic material during said hot forming step, with the plastic material of the at least one sheet of plastic material which enters into said asperities when it is softened by heat during said hot forming step.