Transcript Electrohydraulic Forming of Sheet Metal February 13, 2003 Rachel Sharp

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
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Aerospace
Marine
Power Generation
Offshore Industries
Architectural
Turbine engines
Titanium Alloys
• Alpha Titanium Alloys:
– Lowest strength, formable, weldable
– Yield strength: from 25ksi – 70ksi
• Alpha/Beta Alloys
– High strength, moderate creep resistance
– Yield strength: from 125ksi – 175+ksi
• Near Alpha Alloys
– Medium strength, high creep resistance
• Near Beta Alloys
– Meta-stable, lack ductility, low creep resistance
– Yield strength: from 115ksi – 200+ksi
High strength Titanium alloys:
Ti-6Al-4V ELI Grade 23
• Ti-6Al-4V ELI
– Contains 0.13% max oxygen, improving ductility and fracture
toughness
Mechanical Properties: at 25°C
Density (×1000 kg/m3) 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 & 3D 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