Japanese car manufacturer Honda Motor Company has announced that it has developed a technology that allows steel and aluminium to be joined.

Honda says the innovation will allow it to manufacture weight-saving vehicle doors that combine a steel structure with an aluminium outer skin.

Joining together dissimilar metals may sound simple, notes the company, but requires a combination of no fewer than three separate new technologies to enable the production of doors with aluminium outer panels.

These include, firstly, a proprietary ‘3D Lock Seam structure’ (3DLS), which involves mechanically joining steel and aluminium panels through twice-over layering and hemming.

In addition, Honda had to use a highly anticorrosive steel for the inner panel, while developing a different panel shape that would ensure that the gap between the inner and outer panels could be filled with an adhesive agent.

Finally, thermal deformation was prevented by employing an adhesive agent with a low elastic modulus, while the position of the 3DLS system was also optimised to address deformation.

By developing and using these technologies, Honda was able to eliminate the spot-welding process required to join conventional steel door panels. At the same time, the new processes could be implemented on existing production lines.

Honda says the technologies form part of its “ongoing commitment to improving the fuel economy and the dynamic performance of its vehicles”.

The new steel-and-aluminium doors are around 17% lighter than a normal steel door panel.

Further, since the weight is trimmed from the lateral extremities of the vehicle, the centre of gravity becomes more centralised, which benefits stability and handling, adds the company.

It notes that the new weight-saving technology represents the latest in a series of efforts to reduce vehicle weight “in the interests of lower emissions and greater efficiency”.

Honda’s Acura luxury brand will be the first to adopt the new technology when the new Acura RLX goes on sale in the US, but its application will be expanded to include a growing number of Honda models worldwide.