HYDROFORMING Presented by: Byron Erath Duane Ellsworth

OUTLINE: What is Hydroforming How and where is Hydroforming used Materials used in Hydroforming processes Design Considerations Advantages/Disadvantages Economics of Hydroforming Websites and Links Conclusion

HYDROFORMING Hydroforming uses the force of water or hydraulic fluids to shape a single part. There are two types of hydroforming: 1. Tube hydroforming 2. Sheet hydroforming

TUBE HYDROFORMING 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

SHEET HYDROFORMING 2 METHODS: 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. Note: Sheet hydroforming provides a work-hardening effect as the steel is forced against the blanks through fluid pressure.

APPLICATIONS Automotive industry Sanitary use Aerospace Lighter, stiffer parts Chevy SSR Frame

APPLICATIONS (CONT) 1. Body shell 2. Driving shaft 3. Assembled camshaft 4. Exhaust systems 5. Engine cooling system 6. Radiator frame 7. Safety requirements 8. Engine bearer 9. Integral member 10. Cross member 11. Frame structure parts 12. Axle elements

MATERIALS Steel (mild and harder steels) Stainless Steel Aluminum alloys Research continues to expand the capabilities of the hydroforming process

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 Deformation zone - Deformation mechanics, model used for analysis - Metal flow, velocities, strain rates, strains (kinematics) - Stresses (variation during deformation) 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.)

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!

QUESTIONS???