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 RLX.
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 twice.
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 said.
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 company said.