Strategies for the Heat Treatment of Steel-Aluminium Hybrid Components

Abstract

AbstractThe production of massive steel-aluminium hybrid components by means of massive (hot) forming following a joining operation requires advanced heat treatment strategies for the adjustment of local material properties with maximum joint strengths. For the given process-step sequence, the challenge is that the heat treatment of the hybrid component can only take place in the joined state and after (hot) forming. Consequently, suitable heat treatment strategies must enable both a T6 heat treatment of the aluminium component and a surface hardening of the steel component. It could be shown that the inductive surface hardening of a steel functional surface in the immediate vicinity of the aluminium component can take place without reducing the bond strength. To achieve the desired hardening result, the use of a field former is required. The bond strength could be increased by up to 20% compared to the friction-welded initial conditions by adjusting the parameters of the T6 heat treatment.