It was difficult to join dissimilar materials such as metallic material and polymer. Conventional joining processes of these materials were mechanical fastening, using adhesion, thermal pressing, laser welding and so on. These processes had disadvantages such as expensive apparatus, restriction of dimension of products and lack of anti-weather resistance.Friction Stir Welding (FSW), which was one of the solid state joinings, was available as a joining process for dissimilar metals. However, in case of joining metal and polymer, it was not available to use the tool for FSW. So we proposed Friction Lap Process to join a metallic material with a polymer and investigated mechanical and metallurgical properties of this dissimilar joint. Itwas described in this paper that joining mechanism is discussed with evaluation of microstructure at the interface between aluminum alloy and polymer. High density polyethylene was not able to be joined for as received aluminum alloy. Anodizing was effective to join with these materials.
