Transplantation von thermisch gespritzten verschleißschutzschichten auf druckgussteile aus leichtmetalllegierungen

By manufacturing structured functional-surface coated composites using suitable materials, the properties of components? surfaces can be specifically matched to their requirements which the specified substrate material can not, or can only partially, fulfil. In conventional process chains, thermal spraying and structuring by milling are independent stages in the component?s final processing phase. Using the procedure introduced here, thermal spraying is to be directly integrated into the high pressure die casting process. In this way, a manufacturing procedure for coated castings with functionalized surfaces is realised which, as far as possible, eliminates the finishing operation of coated cast parts. In contrast to conventional coating processes, the coating-layer is not applied to the component but to the casting mould or to the corresponding inserts and is transferred to the component as a structured functional-surface during each cast. Transferring this type of coating from the tooling surface to the casting; which is also referred to as transplant coating, requires a narrow process-window with respect to the coating adhesion to both the tooling surface and the cast part. The coating adhesion at the tooling surface must be high enough such that the coating is not detached during either the coating or the mould filling processes, but also low enough to be completely detached from the tooling during mould stripping and be able to be removed together with the cast part. For this reason, the initial priority of the current investigations is to obtain a specific coating adhesion by adapting both the tooling surface, which is manufactured by milling, as well as the coating systems and the atmospheric plasma spray?s parameters for the most precise moulding of such plasma sprayed structures. Furthermore, investigations are introduced on forming composites from the cast material and the coating materials and results are presented of preliminary casting tests for transplanting thermally sprayed coatings onto aluminium and magnesium alloys during high pressure die casting.