Single Point Incremental Forming : A study of Forming Parameters, Forming limits and Part accuracy of Aluminium 2024, 6061 and 7475 alloys

Sammanfattning: Nowadays there is an increasingly demanding need for the development of agile manufacturing techniques that can easily be adaptable to a constant introduction of new products in the market. Single point incremental forming (SPIF) is a new innovative and feasible solution for the rapid prototyping and the manufacturing of small batch sheet parts. The process is carried out at room temperature (cold forming) and requires a CNC machining centre, a spherical tip tool and a simple support to fix the sheet being formed. This work studied the effects of step size, angle, spindle speed, and feed rate on the forming limits of Aluminium alloys namely AA 2024, AA 6061 and AA 7475 in soft annealed condition. The Study also includes measuring the strain path and determination of maximum forming limit angles for the above mentioned alloys. This thesis provides a better understanding of the influence of rotating tool in the occurrence of fracture without previous necking or fracture following previous necking. Surface and geometric accuracy of the parts manufactured was also studied and comparisons were made between the CAD files and the actual manufactured parts and then corrections were made accordingly. The main contribution of this thesis to Single stage SPIF was the successful manufacturing of a Cone shaped parts with almost vertical walls.