Question

Plastically deforming a metal specimen near room temperature generally leads to which of the following property changes? 5. (a) An increased tensile strength and a decreased ductility (b) A decreased tensile strength and an increased ductility c) An increased tensile strength and an increased ductility (d) A decreased tensile strength and a decreased ductility

Answer 1

Answer:

The answer is (a) An increased tensile strength and a decreased ductility.

Explanation:

When a metal specimen is plastically deformed near room temperature, it implies that the metal specimen is being cold worked (it is undergoing cold working), or it’s shape is being changed without applying heat. Cold working generally leads to an increase in tensile strength and yield strength, and a decrease in ductility.

Answer 2

Answer:

Option a) An increased tensile strength and decreased ductility.

Explanation:

Plastic deformation is when the material once reshaped under applied stress is not able to regain its original shape and is deformed permanently even after the removal of the applied force on a metal specimen at room temperature.

This process is irreversible and is done at microscopic level by the use of dislocation defects. At room temperatures instead of being removed, these accumulate and acts as pin points thus enhancing the tensile strength of the metal followed by a reduction in its ductility.