Analysis of alloy influence on THE JOINT FORMATION IN compound forging of geared steel-aluminium components

Abstract

In order to reduce CO2 emissions, lightweight constructions and the use of steel-aluminium components have become increasingly important in current product development. When manufacturing such components, the dissimilar chemical and physical properties of these materials lead to major challenges in terms of metallurgical bond formation during joining. In particular, chemical compositions have a major impact on the joint properties and have therefore already been intensively investigated in welding technology. With regard to forming technology, the issue arises whether these findings can be transferred to simultaneous forming and joining for the manufacturing of steel-aluminium components by compound forging. In the scope of this study, aluminium workpieces were therefore alloyed with defined amounts of common welding additives such as zinc, nickel and silicon using powder metallurgy. Subsequently, these workpieces were forged together with steel and subjected to metallographic examination. The studies show that compound forging of the used alloy configurations is basically possiblehowever, bond formation varies significantly with different chemical composition. Alloying with zinc and silicon results in a reduced liquidus temperature and consequently in melting. In contrast, alloying with nickel leads to an extended joining zone and benefits the maximal mechanical load capacity.