Imperfection_part 1

Which type of atomic bond is commonly found in metals?

• Ionic bond

• Covalent bond

• Metallic bond

• Hydrogen bond

What is the primary crystal structure of aluminum?

• BCC (Body-Centered Cubic)

• FCC (Face-Centered Cubic)

• HCP (Hexagonal Close-Packed)

• Simple Cubic

Plastic deformation in metals occurs during which processes?

• Melting and freezing

• Rolling, forging, and high-pressure torsion

• Sublimation and condensation

• Ionization and deionization

What is the importance of plastic deformation in metal forming?

• It makes metals brittle

• It reduces the grain size

• It refines the crystal structure

• It does not affect material properties

Which crystal structure is commonly associated with aluminum, copper, gold, and silver?

• BCC

• FCC

• HCP

• Simple Cubic

What is the primary mechanism of plastic deformation in crystal structures?

• Sublimation

• Twisting

• Slipping of atomic planes

• Compression

What is the critical shear stress required for plastic deformation in a single crystal?

• It is always zero

• It depends on temperature

• It depends on the crystal's volume

• It depends on the crystal's atomic density

What is anisotropy in the context of single crystals?

• The ability of a crystal to change its shape easily

• The ability of a crystal to resist plastic deformation

• The variation of material properties with crystallographic direction

• The uniformity of material properties in all directions

In which type of crystal does twinning commonly occur?

• BCC

• FCC

• HCP

• Simple Cubic

How many slip systems are generally required for a metal to be ductile?

• 1

• 3

• 5 or more

• 10 or more