Okada, H., Kamimuki, K., Yoshikawa, S., and Fukada, S., "Refill Friction Spot Joining for Aerospace Application," SAE Technical Paper 2015-01-2614, 2015, doi:10.4271/2015-01-2614.
In the modern aircraft manufacturing, the cost reduction, the manufacturing time reduction, and the weight saving of aircraft are strongly demanded. The Refill Friction Spot Joining [1,2](FSJ, in other words FSSW, Friction Stir Spot Welding), which is one of innovative solid-state joining methodologies based on the Friction Stir Welding, is a promising technology that can replace rivets and fasteners. This technology is expected to offer cost reduction and weight saving for the aircraft manufacturing.In this study, to make stronger and reliable joints, the shoulder-plunging process of Refill FSJ was employed. The weldability of the Alodine or Chromic Acid Anodize coated materials along with a faying-surface sealant was investigated. The joint properties, such as tensile shear strengths and corrosion resistance, were evaluated. As a result, it was found that a sound joint can be made with a faying-surface sealant and its strength was almost the same as that of the joint made without sealant. Moreover, corrosion resistance of the faying surfaces was good.In terms of an automated production, an assembling trail with a 6-axis Refill FSJ robot was performed along with some actual parts. A high quality production without any distortion was achieved.