Experimental investigations on the single point incremental forming of a titanium alloy component combining static heating with high tool rotation speed

The present work focuses the attention on the Single Point Incremental Forming (SPIF) process of a scaled car door shell made by Titanium alloy (Ti6Al4V). The effect of a temperature increase contemporary due to electric static heating and tool rotation speed was investigated. Preliminary tensile tests allowed to define the temperature level to be assured on the sheet in order to determine a consistent flow stress reduction. SPIF tests were carried out adopting rotation speed in the range 800–1600 RPM, while simultaneously changing the pitch value in the range 0.5–1.0 mm. Temperature during the forming process was continuously measured in the central area of the blank using a pyrometer. In addition a digital image correlation system was used for measuring the strain distribution over the formed part. The combination of the two approaches (heating by both electric bands and high tool rotation speed) revealed to be a feasible solution for manufacturing hard to work materials like Ti alloys, since the investigated case study was successfully formed by SPIF. In addition, a positive effect of the tool rotation speed in stabilizing the necking (thus allowing to reach higher level of stretching) was recognised.