CHICAGO Honda Motor Co.
Ltd. says it has developed a trio of technologies that combine
steel and aluminum and is applying them to mass-produced
vehicles, initially in the North American model of the Acura
The first commercial application
of the technologies joins an aluminum outer-door
panelconventionally made from steelto the steel
inner-door panel, the Tokyo-based automaker said.
Honda devised new methods to
prevent electrical corrosion and thermal deformation caused by
the different expansion rates of steel and aluminum:
For the outer-door panel,
Honda developed a "3-D lock seam" structure, in which the steel
panel and aluminum panel are layered and hemmed together
To prevent electrical
corrosion, Honda used a highly anticorrosive steel for the
inner panel and a new form that assures the complete filling of
gaps with an adhesive agent.
To control thermal
deformation, Honda is using an adhesive agent with low elastic
modulus, which allows it to stretch more readily, and optimized
the positioning of the 3-D lock seam.
By combining these techniques,
Honda eliminates a spot welding process that is usually
necessary for joining conventional steel door panels. The
methods can be applied on existing production lines, Honda
By using the metal-joining technologies, Honda said the
weight in the steel-aluminum doors will be 17 percent less than
that of all-steel door panels. Weight reduction along the
vehicles outer body also shifts the vehicles point
of gravity closer to its center, improving maneuverability, the