Q. 1
(a) What are different types of solid-solid interfaces? Mention them. 2
(b) Show a low angle tilt boundary by simple schematic diagram? What is the angular range
for low angle boundary? 2+1
(c) How does a coherent twin boundary differ from an incoherent twin boundary? 2
(d) For FCC Ni (lattice parameter = 0.361 nm) tilt boundary (tilt angle = 5 degrees), estimate the
spacing between dislocations? 3
Solutions:
Answer
(a) Three types: Coherent, Semicoherent and Incoherent
(b) Simple schematic diagram of low angle grain boundary. A low-angle tilt boundary is an
array of parallel edge dislocations