High Precision Incremental Forming Using Porous Backing Plate

Incremental forming using porous material for backing plate was performed. First, five types of porous materials with different hardness were prepared and subjected to compression test to investigate their mechanical properties. The compressive strengths of the porous materials were almost same and approximately 65 kPa or 120kPa. Next an A1050-H24 sheet was formed with the backing plate of porous material placed under the sheet. Sheets were formed into truncated cone shape by a tool path that circumscribed from the outside of the circle to the center on the contour lines. The forming was performed with an initial diameter of 80 mm, a height of 40 mm, and a forming angle of 30 degrees as a standard, and the height and angle were varied. Compared to the cases with and without porous material, the droop deformation at the flange was reduced about 1 mm by using porous material for backing plate.