Sept. 9, 2012
Honda Motor Company announced that it has newly developed a technology for the continuous welding of the dissimilar metals of steel and aluminum and applied it for the first time in the world to the subframe of a mass-production vehicle, a key component of a vehicle body frame. Honda will adopt this technology first to the North American version of the all-new 2013 Accord, which will go on sale in the United States on September 19, 2012, and will expand application sequentially to other models.
|Conceptual diagram of FSW of dissimilar metals|
Striving to reduce vehicle weight in order to increase fuel economy, Honda focused on Friction Stir Welding (FSW) and developed a new technology for the continuous welding of steel and aluminum. This technology generates a new and stable metallic bonding between steel and aluminum by moving a rotating tool on the top of the aluminum which is lapped over the steel with high pressure. As a result, the welding strength becomes equal to or beyond conventional Metal Inert Gas (MIG) welding*1.
This new technology contributes to an improvement in fuel economy by reducing body weight by 25% compared to a conventional steel subframe. In addition, electricity consumption during the welding process is reduced by approximately 50%. It also enabled a change in the structure of the subframe and the mounting point of suspension, which increased the rigidity of the mounting point by 20% and also contributed to the vehicle’s dynamic performance.
Furthermore, Honda established a new method to apply this technology to mass-production vehicles. Conventionally, FSW required use of large equipment, but Honda developed a FSW continuous welding system applied to a highly versatile industrial robot. This system also can be used for aluminum-to-aluminum welding and thus, the welding system with the same specifications can be used for production of a full-aluminum subframe.
Honda also developed a non-destructive inspection system*2 using a highly-sensitive infrared camera and laser beam, which enables an in-line inspection of the bonding location for every unit.
*1 A welding technique most commonly used for welding of identical materials such as steel-to-steel or aluminum-to-aluminum
*2A system that evaluates quality without actually destructing the parts