Formability refers to the ability of a material, typically a metal or alloy, to undergo deformation and shaping processes without rupturing or experiencing excessive defects. It is a critical characteristic in manufacturing processes such as metal forming, stamping, forging, and extrusion, where raw materials are shaped into final products. The formability of a material is influenced by its mechanical properties, including ductility, malleability, and the ability to undergo plastic deformation without failure.

1. Formability & Fracture of
Metals
Mr. MANICKAVASAHAM G, B.E., M.E., (Ph.D.)
Assistant Professor,
Department of Mechanical Engineering,
Mookambigai College of Engineering,
Pudukkottai-622502, Tamil Nadu, India.
Email:mv8128351@gmail.com
Dr. R.Narayanasamy, B.E., M.Tech., M.Engg., Ph.D., (D.Sc.)
Retired Professor (HAG),
Department of Production Engineering,
National Institute of Technology,
Tiruchirappalli-620015, Tamil Nadu, India.
Email: narayan19355@gmail.com

2.  Formability refers to the ability of a material, typically a metal or alloy, to undergo
deformation and shaping processes without rupturing or experiencing excessive
defects.
 It is a critical characteristic in manufacturing processes such as metal forming,
stamping, forging, and extrusion, where raw materials are shaped into final products.
 The formability of a material is influenced by its mechanical properties, including
ductility, malleability, and the ability to undergo plastic deformation without failure.
Define: Formability

3.  Ductility is a mechanical property of materials that describes their ability to undergo
significant plastic deformation before rupture or breakage.
 A material with high ductility can be stretched or bent without fracturing, allowing it
to be drawn into thin wires or formed into various shapes.
 Ductility is the opposite of brittleness, where a material tends to fracture or break
with little deformation.
Define: Ductility

4.  Malleability is a property of materials that describes their ability to withstand
deformation under compressive stress.
 A highly malleable material can be shaped, hammered, or rolled into thin sheets
without breaking or cracking.
 Malleability is often associated with ductility, and both properties are important in
various manufacturing processes, especially those involving metals.
Define: Malleability

5.  Formability tests are conducted to assess the ability of materials to undergo deformation
without failure during manufacturing processes such as bending, stretching, stamping, or
deep drawing.
 There are several tests and methods employed to evaluate the formability of materials.
Formability Tests

6.  Tensile Test:
• Determines the material's ability to deform under tensile (pulling or stretching) stress.
• Provides information on elongation, ultimate tensile strength, and yield strength.
 Bend Test:
• Evaluates a material's ductility and resistance to cracking when subjected to bending
forces.
• Different variations include the simple bend test and the more complex Erichsen
cupping test.
Some Common Formability Tests Include:
Cont.

7.  Deep Drawing Test:
• Mimics the conditions of deep drawing processes used in the fabrication of sheet metal
components.
• Measures the ability of a material to undergo significant deformation without tearing.
 Hole Expansion Test:
• Assesses the stretch flange ability of a material by measuring its resistance to cracking around
a punched hole.
 Cupping Test:
• Measures the deep drawing properties of sheet metal by forming a cup-shaped specimen.
Cont.

8.  Nakazima Test:
• Evaluates the stretch formability of a material by forming a flat strip into a cylindrical shape.
 Bulge Test:
• Determines the material's ability to expand without rupturing by applying internal pressure to a
sheet.
 Hydroforming Test:
• Involves forming a tube or sheet metal using fluid pressure to assess the material's formability
under different conditions.
 Erichsen Cupping Test:
• Measures the deep drawing properties of sheet metal by assessing the deformation of a
hemispherical punch.
Cont.

9. • These tests are often tailored to specific manufacturing processes and industry
standards.
• The results of formability tests guide material selection for applications where shaping
and deformation are critical considerations.
Cont.

10. Plot for Tensile Test (for Ductile Metals)

11. Formability Test Tool Setup

12. Bulge Test (for Sheet Metal)

13. Deep Draw Test

14. Cont.

15. Formability Test Samples

16. Bend Test

17. Erichsen Cupping Test

18. Erichsen Cup With Fracture

34. References:
 Authors of Technical articles and Scopus Journals are
Acknowledged.
 METAL FORMING
Mechanics and Metallurgy
FOURTH EDITION
WILLIAM F. HOSFORD
University of Michigan, Ann Arbor
ROBERT M. CADDELL

35. Thank You