Question

1. What is ductile fracture? What is brittle fracture? (10 pts) 8. Please describe the differences between ductile fracture and brittle fracture. (10 pts)

Answer 1

Ductile fracture - In very simple term, it is actually the thinning of middle area of a specimen. In engineering terms, it is also called as necking or can be attributed to decrease in cross sectional area. It occurs prior to actual fracture. There is considerable permanent or plastic deformation in the region of ductile fracture. In this, we will notice the plastic deformation before the specimen breaks.

Brittle fracture - In this, there is sudden break in the specimen. It occurs without any prior plastic deformation. In engineering words, it is sudden, very rapid cracking of equipment under stress where the material exhibited little or no evidence of ductility. The fracture surface of a brittle failure is usually reasonably smooth.

Difference between ductile and brittle fracture

Ductile fracture	Brittle fracture
Large plastic deformation	Minimal or no plastic deformation
It involves necking prior to fracture	No necking involved
It occurs in Face centered materials	occurs in B.C.C usually
very rough surface after fracture	very smooth surface after fracture
occurs with warning like necking, expenditure of energy	no warning prior to fracture