Product Code: JLA_20_4_224

Authors:
C. von der Haar
L. Engelbrecht
O. Meier
A. Ostendorf
H. Haferkamp
Laser Zentrum Hannover e.V., Hollerithallee 8, 30419 Hannover, Germany

A consistent lightweight concept necessitates the combination of different lightweight materials. Because of the significant weight reduction, multimaterial design is becoming more and more interesting for the transportation industry. Mixed material concepts are partially limited because of the insufficient deformation behavior of the joining seams. To overcome this limitation, a brazing process has been developed in which aluminium and steel can be joined, with an enhanced deformation behaviour. Tailored hybrid blanks with deep drawing ratios of 1.9 are possible. Process studies, metallographic analyses, and tensile tests were carried out for AA6016 sheets in combination with DX56D. The AA6016 surface has to be activated using a noncorrosive flux. Although it is possible to avoid melting of the aluminium base metal, intermetallic FeAl compounds occur and were characterized using energy dispersive x-ray analysis. It was proven that the intermetallic compounds affect the mechanical characteristics of the seam. During tensile tests, butt seams show approximately 70% of the strength of the weaker base metal. The results of cupping tests show the ultimate possibility of using tailored hybrid blanks in a various number of applications.