Product Code: ICAL06_1702

Laser Beam Brazing of Steel-Aluminium Tailored Hybrid Blanks
Authors:
Andreas Ostendorf, Laser Zentrum Hannover; Hannover Germany
Heinz Haferkamp, Laser Zentrum Hannover; Hnnover Germany
Lars Engelbrecht, Laser Zentrum Hannover E.V.; Hannover GERMANY
Oliver Meier, Laser Zentrum Hannover; Hannover Germany
Presented at ICALEO 2006

The prerequisite for a consistent lightweight construction is the exhaustive utilization of the weight-specific characteristics of different construction materials. Therefore, multi-material design is becoming more and more interesting to the transportation industry. However, the potential of mixed compounds for lightweight construction can not be entirely exploited because of the lack of adequate joining processes. For the manufacture of tailored hybrid blanks made of steel and aluminium the Laser Zentrum Hannover developed a laser brazing process. Process studies, metallographic analyses and tensile tests were carried out for connections of AA6016 sheets in combination with various steel sheet metal grades. Different zinc solders were used as filler metal. Although it is thereby possible to avoid the melting of the aluminium base metal, intermetallic FeAl phases developed and were characterized using SEM and EDX analysis. It was thus proven that the intermetallic phases affect the mechanic characteristics of the seam. However, the weaker base metal of overlap joints fails in tensile tests. Depending on the seam volume butt joints show approx. 80% of the strength of the weaker base metal. By means of cupping tests a sufficient deformation capacity of the tailored hybrid blanks could be demonstrated for a specific combination of materials.