Incremental Sheet Forming

Kathryn Jackson1st December 2005

Overview

• What is ISF?• Why is ISF potentially very useful?• Why is ISF not more widely applied already?• What are my research projects?

1. What is ISF?

Incremental sheet forming (ISF) is metal forming by a progression of

localised deformation

y

zx

Tooling and Workpiece Support

2. Why is ISF potentially very useful?

Why sheet metal forming?• A practical way to form a thin 3D shell

Why sheet metal forming?• Metal properties are desirable for many

applications

Why sheet metal forming?

Sheet Metal Applications

Why choose ISF over other sheet metal forming processes?

Pressing

Stamping

Deep drawingSpinning

Flow forming

Hydroforming

Peen forming

Incremental sheet forming

Laser forming

Evaluation of ISF

Economic

EcologicalMechanical

Mechanical Evaluation of ISFMin Requirement Max Requirement

Maximum dimension 20mm 5m

Surface finish ‘good’ ‘Very good’

Wall angle 0o 90o

Geometric tolerance 0.5mm 5mm

Minimum feature radius 1mm 50mm

Sheet thickness 0.4mm 3mm

Mechanical evaluation shows overlap of process window with typical requirements is good

Economic Evaluation of ISF

Cost per product or speed per product

Batch size

~200 to 1200 parts

Processes requiring dies (stamping, deep drawing)

Incremental sheet forming

Economic viability for small batch sizes

Economic Evaluation of ISF

Medical

Repair/replacementDecorative

Architectural

Industrial

Personalisation

Possible Applications

Ecological Evaluation of ISF

✔✔Smaller machines

✔Lower forming forces

✔✔Reworking instead of reprocessing or scrapping

✔Localised production –reduction of transportation

✔✔No die required

Materials savings

Energy savings

ISF has strong ecological advantages

Summary of Evaluation

ISF is potentially a very useful sheet metal forming process….

….But there is hardly any application in industry already

3. Why is ISF not more widely applied already?

Why?

In reality the ‘optimum’ mechanical capabilities are usually not achieved

Major Challenges for ISF• There is a complicated interaction between the

process design and process capabilities, which means the process is usually not optimised

• Accuracy relies on complicated tool path optimisation or expensive workpiece support

• Machinery and tooling design restrict the ‘design space’

• Not well known

4. What are my research projects?

ISF Research at the IfM4. Flexible support of the workpiece1. Tool force and geometry prediction

y

zx

2. Sandwich panel forming

3. Real time process control using force feedback

5. Design of the ‘ideal’ incremental sheet forming machine

Thank you!