Metal Forming Simulations

Their Use in Aluminum FormingApplications

M. Sc. Canderim Önder; Alutec Metallwaren GmbH & Co. KG

11. Simufact Roundtable; 13th October 2009

Outline

• Company profile

• Determination phases of the metal forming simulation software selection

• Case studies

Company Profile

• alutec supplies creative solutions by the aluminum impact extrusion method.

• alutec is an expert on cold forming of aluminum

• Machining centers realize metal cutting operations

• Founded in 1988, and located in Sternenfels

• ~200 employees

• 26 million € turnover

• Annual processed tonnage : 1250 ton.

Main Product Groups

Housings

• Engine management

• Airbag control

• Ultrasonic sensors

• Path measurement

• Shock absorber

Heat Sinks

• Air conditioning electronicsin motor cars

• LED electronics in motor cars

• PC electronics

Mechanical Components

• Pistons / push rods for gearbox control

• Pistons for wheel brakes in motor cars

• Pistons for hand brakes in commercial vehicles

… and assemblies

World Wide Custumers

USA

Mexico

France

Spain

Germany

UK

The NetherlandsDenmark

Czech Republic

Poland

Austria

KoreaJapan

Determination Phases of a Metal FormingSimulation Software

• Intention of the board

• Assignment of a responsible engineer

• Presenting the abilities of the available software on the market

• Determination of the technical needs

Determination Phases of a Metal Forming Simulation Software• Software Comparison (Self-evaluation / proof of known defects)

Material: AW-6082 AlMgSi1

Press Type: Crank Press

Forming Errors

•Sucking defects at the base

•Uncontrolled diameter of the center hole

Aim

• Visualization of the defects in 3 FE softwares

• To reveal the flowlines of the part and compare by FE results

Determination Phases of a Metal Forming Simulation SoftwareNone of the softwares could visualize sucking defect

Contact Pressure Distribution:

SimufactFlowline Visualisation:

Determination Phases of a Metal FormingSimulation Software

Flowline Comparison

Simufact

More realistic

Determination Phases of a Metal Forming Simulation Software

Underfilling or flow through defect

Lap formation

OR flw. through

Flow through defect!! Only in one corner.

Determination Phases of a Metal Forming Simulation SoftwareBuckling Ratio

(Critical h/d ratio has been determined by experiments. At the critical ratios FE simulations must have shown the initiation of the buckling)

Simufact√ √

Case Studies

Die Failure Prevention (1)

• The part is produced by forward can extrusion. Tool life was only a few.

Die Failure Prevention (2)

• Principal max. Stress distribution during forming

Die Failure Prevention (3)

• Analyses showed that the corner of the die needs to have a positive pre-stress.

• On the figure at the right, the new idea to prolong the die life is sketched; the parameters h and ∆z are to be optimized

• The tooling is mounted to the rest of the die part with a bolt. The prestressing effect of the bolt has been also taken into account

• Optimized configuration at max. punch load. Tooling is still in use

Principal max. stress dist.

1900

Cave on the Product Wall (1)

• During cold forming, bottom and the side walls of the product were deflected

• The whole process has been modeled, including ejection process

forming ejection

• The FE results were identical with the actual product.

Cave on the Product Wall (2)

• The previous product is milled to obtain an aluminum frame.

• To detect if the movement of the chuck causes permanent plastic deformation on the frame, an analysis has been performed on (cold forged + trimmed) part.

Symmetry surface

Symmetry surface

Chuck movement

• A small amount of plastic shape change has been detected because of the chuck movement.

Conclusion

• Especially with its accuracy, Simufact has been selected as metal forming simulation tool by alutec.

• Sucking type failures could be correctly visualized by flowlines

• In 3D applications, FV solution serves a quick evaluation method. But the ultimate results must be verified with FE, unless the process has extreme complexity.

• In some cases, the exact reason of a problem might be understood only if the whole cold forming process history is modeled.

• GP_GUI must be preserved in simufact product group. Its advanced applications and postprocessing capabilities are unique.