2020 Volume 61 Issue 5 Pages 1000-1007
Alternating and one-way tool paths were applied for penetrating tool friction stir incremental forming to compare the forming limit in height without sheet fracture. A truncated cone was formed using 200 mm × 200 mm × 2 mm commercial pure aluminum (JIS: A1050-O) sheets. After the cone was formed, the forming limits in height when employing penetrating tool friction stir incremental forming with alternating tool paths were compared with those formed with one-way tool paths. A tool rotation rate for forming of 1000 rpm, tool feed rate for forming of 1000 mm/min, and wall angle of 45° were used. The forming limit in height with alternating tool paths was approximately 30 mm and the limit in height for one-way tool paths was less than 10 mm. Volume change per unit length in radial direction for both formed sheets with alternating and one-way tool paths were calculated such that the improvement of forming limit in height could be examined. The volume change per unit length observed with alternating tool paths was smaller than for that with one-way tool paths, which means that a more uniform material distribution was achieved when penetrating tool friction stir incremental forming was employed with alternating tool paths.