The document discusses the Erichsen cupping test for evaluating the formability of sheet metals. It defines formability as the ability of a sheet to be formed into a specific shape. Formability depends on parameters like strain hardening coefficient, strain rate sensitivity index, and plastic strain ratio. The Erichsen cupping test involves drawing a hemispherical dome in a sheet metal and visually inspecting it for defects like radial or circumferential cracks that provide information about the material's grain size, anisotropy, and ductility in different directions. Results are compared to standard charts to evaluate formability.

1. Marathwada Mitramandal’s
College of Engineering, Pune
Department of Mechanical Engineering
Subject:- Engineering Materials and
Metallurgy
Topic:- Erichsen cupping test
Course Co-ordinator :- Pavanraj S. Khade.
(Assistant Professor MMCOE, Pune)

2. Formability Testing
• Formability is defined as the ability of a
sheet material to be formed into a specific
shape or configuration.
• Formability of sheet metal is dependent
on the following parameters:
1. Strain hardening coefficient or exponent
(n)
2. Strain rate sensitivity index (SRS)
3. Plastic strain ratio (r)
4. Strain distributions:

3. Formability Testing
• Erichsen Cupping Test

4. Formability Testing
• Erichsen Cupping Test

5. Formability Testing
Radial cracks Circumferential
cracks

6. • Visual inspection of dome gives
1. Rough appearance- Large grain size
2. Radial cracks- Equal strength of sheet in all
directions
3. Circumferential cracks- Anisotropic property
of sheet
4. One direction crack- variation in ductility in
different direction

7. Formability Testing
• Erichsen Standard Chart