126 Development of Friction Stir Incremental Forming Process and Its Application to Forming of Magnesium Alloy Sheets

Abstract

To form magnesium alloy sheets without heating, friction stir incremental forming process was developed. AZ31 and AZ61 sheets with 0.5mm or 0.7mm thickness were used and formed into frustum of pyramid shapes. Tool rotation rate, tool feed rate and half apex angle of pyramid were changed. Not only formability but also hardness and tensile strength of formed part were measured. From the experimental results, AZ31 sheet with 0.5mm thickness formed into a frustum of pyramid shape with the half apex angle of 25° by the developed method showed 137% elongation, and its tensile strength was about 10% higher than that of not formed one. AZ31 sheet with 0.7mm thickness and AZ61 sheet with 0.5mm thickness were also formed into a frustum of pyramid shape with the half apex angle of 45°, successively.