Toughness

Definition and Measurement of Toughness

• Toughness is related to the area under the stress-strain curve.
• A material must be both strong and ductile to be tough.
• Brittle materials lack ductility and are not tough.
• Toughness indicates how much energy a material can absorb before rupturing.
• Toughness can be determined by integrating the stress-strain curve.
• The toughness of a material can be measured using a small specimen and a testing machine.
• The energy absorbed by the specimen during deformation is a measure of toughness.
• The Charpy and Izod notched impact strength tests are used to determine toughness.
• ASTM tests are typical methods used to determine toughness.
• Tensile toughness is measured in units of joule per cubic meter (J·m) or newton-meter per cubic meter (N·m·m).
• In US customary units, it is measured in inch-pound-force per cubic inch (in·lbf·in).
• The unit of tensile toughness can be calculated using the area under the stress-strain curve.
• Tensile toughness is the product of force per unit area and deformation per unit length.
• Tensile toughness is expressed as N·m·m or J·m.

Toughest Material

• An alloy made of chromium, cobalt, and nickel (CrCoNi) is currently the toughest material discovered.
• It resists fracturing even at extremely cold temperatures close to absolute zero.
• The CrCoNi alloy is being considered for use in building spacecraft.
• The toughness of the material allows it to withstand high stresses and strains.
• The alloy's composition provides a balance of strength and ductility.

Relationship to Hardness

• Hardness is another material property related to toughness.

Techniques and Studies Related to Toughness

• Rubber toughening is a technique used to improve the toughness of materials.
• Shock mechanics studies the behavior of materials under sudden impact or load.
• Tablet hardness testing is a method to determine the hardness and toughness of tablets.

Toughness Data Sources