In the malleability and ductility test, if the bent piece cracks on the outside, it indicates a lack of which property?

In the malleability and ductility test, if the bent piece cracks on the outside, it indicates a lack of which property?

• A. Ductility
• B. Malleability
• C. Elasticity
• D. Toughness

Answer: (B)

In bending, the outer surface is under tension while the inner surface is under compression. If a material can stretch and deform plastically under that tensile stress, it stays intact and forms a smooth bend. But when the outer surface cracks, it shows the metal can’t elongate easily under tension—it lacks ductility. Malleability relates to deforming under compression, not the tensile stress seen on the outer surface in this test, so cracking here doesn’t indicate a lack of malleability. Elasticity is about reversible deformation, which isn’t what this observation tests, and toughness is about energy absorbed before fracture, which is related but not the direct cue from this bend test. So the crack on the outside points to insufficient ductility.

In bending, the outer surface is under tension while the inner surface is under compression. If a material can stretch and deform plastically under that tensile stress, it stays intact and forms a smooth bend. But when the outer surface cracks, it shows the metal can’t elongate easily under tension—it lacks ductility. Malleability relates to deforming under compression, not the tensile stress seen on the outer surface in this test, so cracking here doesn’t indicate a lack of malleability. Elasticity is about reversible deformation, which isn’t what this observation tests, and toughness is about energy absorbed before fracture, which is related but not the direct cue from this bend test. So the crack on the outside points to insufficient ductility.