The process of alloying in other atoms to increase the yield strength

The process of deforming the metal to increase the yield strength

The process of changing the size of the metal crystals by heat treatment to increase the yield strength

The process of deforming the metal to increase the modulus

Covalent bonds

Secondary bonds

Metallic bonds

Ionic bonds

Plastic deformation occurs when bonds in a material are broken

Elastic deformation is recoverable because none of the bonds within the material are broken

Elastic and plastic deformation are mutually exclusive; only one of them can occur at a given moment

Plastic deformation occurs in various different types of material, not just plastics

Elastic modulus is dependent on the types of bonds that are present in a material, as well as other factors

UTS < 0.2% proof stress < Yield stress

Yield stress < UTS < 0.2% proof stress

0.2% proof stress < Yield stress < UTS

0.2% proof stress < UTS < Yield stress

UTS  < Yield stress < 0.2% proof stress

Yield stress < 0.2% proof stress < UTS

Because the fracture strain is the sum of elastic and plastic strain.

Because the fracture strain is a measure of engineering or nominal strain, not true strain.

Because the fracture strain cannot be measured accurately during a test.

Because the fracture strain is only measured at fracture.

Because the fracture strain does not take into account work hardening.