Lightweight composite hybrid part

Evonik’s adhesion promoter was used to bond a metal and a long fiber reinforced thermoplastic (LFT) to make the control arms of a car rear axle.
Evonik’s adhesion promoter was used to bond a metal and a long fiber reinforced thermoplastic (LFT) to make the control arms of a car rear axle.

Materials company Evonik says that it has supplied an adhesion promotor for a hybrid part that helped reduce weight by 20%. The company’s adhesion promoter VESTAMELT Hylink was used to bond a metal and a long fiber reinforced thermoplastic (LFT) to make the  control arms of a car rear axle. Typically, the metal and plastic components of hybrid parts are bonded with frictional or form fit elements such as screws, rivets, or by overmolding and insert molding. The challenge in the case at hand was to come up with a different production process that includes the forming of the metal plate as well as the molding of the long-fiber-reinforced thermoplastic, taking into account reinforcement ribs and a variable wall-thickness distribution of the fiber-reinforced plastic. Using a multiform process, a long glass fiber reinforced compound produced by Weber Fibertech GmbH was extruded to give a moldable semi-finished product. Along with a preheated metal plate coated with VESTAMELT Hylink, the product is transferred in the molten state into a mold. In a one-step production process both parts are pressed into shape and simultaneously joined together. The mold incorporates the desired negative form for the ribbing and the forming of the metal, while by combining steel and LFT, materials of two different types (two dissimilar materials), it has been possible to reduce the thickness of the steel plate by more than a millimeter from the original. This results in about 20% less total weight of the demonstration longitudinal and transverse control arms, Evonik says.

This story is reprinted from material from Evonikwith editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier.