Electrohydraulic Forming of Sheet Metal February 13 2003

Electrohydraulic Forming of Sheet Metal February 13, 2003 Rachel Sharp Corinne Packard Isaac Feitler Hao Hu

Advantages of High Velocity Metalforming • Complex pieces can be formed without using several different parts (seamless) • Closer tolerances can be achieved • Difficult to form alloys can be used • Waste is significantly reduced

Experiment Setup • Pressure Vessel • Die • Capacitor Bank & Electronic System

Titanium • Good Strength to Weight ratio • Corrosion Resistant • Main Uses – Aerospace – Marine – Power Generation – Offshore Industries – Architectural – Turbine engines

Titanium Alloys • Alpha Titanium Alloys: – Lowest strength, formable, weldable – Yield strength: from 25 ksi – 70 ksi • Alpha/Beta Alloys – High strength, moderate creep resistance – Yield strength: from 125 ksi – 175+ksi • Near Alpha Alloys – Medium strength, high creep resistance • Near Beta Alloys – Meta-stable, lack ductility, low creep resistance – Yield strength: from 115 ksi – 200+ksi

High strength Titanium alloys: Ti-6 Al-4 V ELI Grade 23 • Ti-6 Al-4 V ELI – Contains 0. 13% max oxygen, improving ductility and fracture toughness Mechanical Properties: at 25°C Density (× 1000 kg/m 3) 4. 43 Poisson's Ratio 0. 34200001 Elastic Modulus (GPa) 113. 8 Tensile Strength (Mpa) 896 Yield Strength (Mpa) Elongation (%) 15 Hardness (HRC) 35 827 Reduction in Area (%) 35 Impact Strength (J) Thermal Properties: 24 between 20°C and 100°C Thermal Expansion (10 -6/ºC) 8. 6

Car Mirror Casing • Unique shape presents challenge. • Titanium mirror casing is very marketable. • Strength of Ti alloy might prevent inconveniences such as dents, etc.

Gantt Chart Week 2 3 4 5 6 7 8 9 10 11 12 13 14 Vessel design and parts acquisition Capacitor bank acquisition (at MIT, outside of MIT if needed) Pressure Vessel assembly CAD & 3 D printing of mold Casting of mold Break 1 Electrohydraulic test Funnel formation Final part formation Presentation preparation Pressure Vessel Capacitor Bank Mold Electrohydraulic forming Final Presentation

Risks and Contingencies • Relying on outside sources for key components such as capacitor bank. • Large turnaround time for experiment setup • Mirror casing shape potentially too complicated