Osaka University

Rintaro Ueji

Hidetoshi Fujii

Yoshiaki Morisada

A low-temperature joining method effectively suppresses reductions in the mechanical properties of a junction of various types of high-tensile steel or aluminum, and of a heat-affected zone; and produces a joint structure. A method for joining two metal materials by forming a joint interface in which the two metal materials face each other at a joint portion and plunge a rotation tool caused to rotate at a prescribed speed into the joint, the method for low-temperature joining of metal materials characterized in that the peripheral velocity of the outermost periphery of the rotation tool is set to 51 mm/s or less, whereby the recrystallization temperature inherent to the metal materials is reduced by introducing a large strain to the joint, and recrystallized grains are generated at the joint interface by setting the joining temperature to less than the recrystallization temperature inherent to the metal materials.

Method for low-temperature joining of metal materials, and joint structure

Provided are a simple and effective friction welding method that can suppress increases in hardness of the welded part and reductions in hardness (strength) in the heat affected zone regardless of the composition of ferrous material, and a welded structure obtained with the same. The present invention relates to a friction welding method wherein surfaces to be welded of two metal members () to be welded are made to slide in contact with each other. The friction welding method is characterized in that at least one of the metal members () to be welded is a ferrous material, and the maximum temperature reached during welding is equal to or less than the Apoint or equal to or less than the Apoint of the ferrous material. The maximum temperature reached during welding is preferably equal to or less than the A1 point of the ferrous material.

Growing community of inventors

Suita, Japan

Rintaro Ueji