US 11,986,901 B2
Friction stir welding tool and friction stir welding method
Hidetoshi Fujii, Suita (JP); Yoshiaki Morisada, Suita (JP); Yusuke Katsu, Nagoya (JP); and Hiroki Takeuchi, Nagoya (JP)
Assigned to NTK CUTTING TOOLS CO., LTD., Komaki (JP); and OSAKA UNIVERSITY, Suita (JP)
Appl. No. 17/291,557
Filed by NGK SPARK PLUG CO., LTD., Nagoya (JP); and OSAKA UNIVERSITY, Osaka (JP)
PCT Filed Mar. 6, 2020, PCT No. PCT/JP2020/009861
§ 371(c)(1), (2) Date May 5, 2021,
PCT Pub. No. WO2020/184483, PCT Pub. Date Sep. 17, 2020.
Claims priority of application No. 2019-042785 (JP), filed on Mar. 8, 2019.
Prior Publication US 2022/0001486 A1, Jan. 6, 2022
Int. Cl. B23K 20/00 (2006.01); B23K 20/12 (2006.01); B23K 103/04 (2006.01)
CPC B23K 20/1255 (2013.01) [B23K 2103/04 (2018.08)] 10 Claims
OG exemplary drawing
 
1. A friction stir welding method characterized in that
plate members are friction stir welded by using a friction stir welding tool including
a shoulder portion, and
a probe portion provided on a bottom surface of the shoulder portion, the probe portion having a length of 5.5 mm or more, the probe portion decreasing in diameter continuously from the bottom surface toward a distal end of the probe portion, and grooving and/or chamfering is not performed on the probe portion such that the probe portion has a smooth surface,
wherein a ceramic material whose main phase is silicon nitride or sialon is used as a base material;
the shoulder portion of the friction stir welding tool is brought into contact with the plate members, while the probe portion of the friction stir welding tool is inserted into the plate members by an amount of 5.5 mm or more;
monitoring reaction forces applied from the plate members to the friction stir welding tool;
holding the position of the friction stir welding tool for a predetermined period of time after the probe portion has been inserted into the plate members; and
laterally moving the friction stir welding tool after the reaction forces applied from the plate members to the friction stir welding tool have decreased below a threshold value.