A Seminar Report

On

HYDROFORMING

Prepared by :-Patel Mehul.APatel Jay

Guided By ;-

D.H.Patel

OUTLINE:

• What is Hydroforming• Types of hydroforming• Application• Design Considerations• Advantages/Disadvantages• Economics of Hydroforming• Reference Websites and Links• Conclusion

HYDROFORMING

Hydroforming is a manufacturing process where liquid pressure is used to form complex shapes.

There are two types of hydroforming:

1) Tube hydroforming 2) Sheet hydroforming

TUBE HYDROFORMING

Outer tool part

Tube

Inner tool part

Section A - A

Upper tool partnot shown

• Used when a complex shape is needed.

• A section of cold-rolled steel tubing is placed in a closed die set.

• A pressurized fluid is introduced

into the ends of the tube.

• The tube is reshaped to the confine of the cavity.

Tube Hydroforminga b

c d

FaxialFaxial

P

e f

SHEET HYDROFORMING

• Sheet steel is forced into a female cavity by water under pressure from a pump or by press action

• Sheet steel is deformed by a male punch, which acts against the fluid under pressure.

APPLICATIONS

• Automotive industry

• Sanitary use

• Aerospace– Lighter, stiffer parts

Chevy SSR Frame

APPLICATIONS (CONT)1. Body shell2. Driving shaft3. Assembled camshaft4. Exhaust systems5. Engine cooling system6. Radiator frame7. Safety requirements8. Engine bearer9. Integral member10. Cross member11. Frame structure parts12. Axle elements

MATERIALS

• Steel (mild and harder steels)

• Stainless Steel

• Aluminum alloys

DESIGN CONSIDERATIONS

• Hydroforming is generally defined as either low-pressure or high pressure.

• The demarcation point is 83MPa• Constant pressure volumetric expansion < 5% required to shape the part = Low pressure > 5% (but < 25%) = High Pressure

DESIGN CONSIDERATIONS

Product

- Geometry, thickness distribution- Dimensional accuracy/tolerances- Surface finish- Microstructure, mechanical and

metallurgical properties, hardness

Tool/Dies

-Geometry of tools

- Material hardness

- Surface conditions

- Stiffness and accuracy

Equipment

- Press capacity

- Speed/production rate

- Force/energy capabilities

- Rigidity and accuracy

Work piece/Material

-Flow stress as a function of strain, strain rate and microstructure

-Workability as a function of strain, strain rate and microstructure

- Surface conditions

- Geometry of tubing ( outside diameter, tube wall thickness, roundness, properties of welding line, etc.)

Deformation zone

-Deformation mechanics, model used for analysis

- Metal flow, velocities, strain rates, strains (kinematics)

- Stresses (variation during deformation)

ADVANTAGES

• Hydroforming draws material into the mold• Part consolidation• Weight reduction through more efficient section

design and tailoring of the wall thickness • Improved structural strength and stiffness• Lower tooling cost due to fewer parts• Fewer secondary operations (no welding of

sections required and holes may be punched during hydroforming)

• Tight dimensional tolerances and low spring back

• Reduced scrap

ADVANTAGES (CONT.) Results compared to conventional steel body structure:

• 50% less weight• 45% less parts (less tools, less assembly)• 45% less welding seams • Tighter tolerances

Volvo Hydroformed Structure concept in Aluminum, (Schuler Hydroforming 1998)

DISADVANTAGES

• Slow cycle time

• Expensive equipment and lack of extensive knowledge base for process and tool design

• Requires new welding techniques for assembly.

ECONOMICS

INFORMATION ON THE WEB

• www.hydroforming.net• www.vari-form.com• www.hdt-gti.com• www.revindustries.com• www.autosteel.org• www.schuler-hydroforming.de• www.egr.msu.edu/~aenader• nsmwww.eng.ohio-state.edu/html/tube_hydroforming.html

CONCLUSION

• Hydroforming is an innovative forming process

• Hydroforming is becoming more popular (ie.automotive and aerospace industries)

• The advantages outweigh the limitations

• Material selection is broad and continues to increase

• Information can be found everywhere!