What is an interface? What are different types of interfaces

What is an interface? What are different types of interfaces

Where two homogeneous bulk phases meet there is a region of finite thickness where the 

properties change, often markedly, as we move from one bulk phase to the other. Such 

regions are known as surfaces or interfaces. Although we may commonly think of a surface 

as being of negligible thickness, in fact, when we are discussing phenomena at a molecular 

level the thickness of the interfacial region is significant and definitely non-zero.

Because there are three types of bulk phase, it is possible to classify interfaces based on the 

nature of the bulk phases that lie on either side of the interface. Thus, there are five types of 

interface:

 

Quiz1

complete solution is here: https://www.iitdocs.com/2026/05/quiz-solution-mse-639-interfaces-and.html

Quiz Solution: MSE 639: Interfaces and Materials Property

 Quiz Solution: MSE 639: Interfaces and Materials Property

Quiz3

Quiz2

Quiz1

For FCC Ni (lattice parameter = 0.361 nm) tilt boundary (tilt angle = 5 degrees), estimate the spacing between dislocations?

For FCC Ni (lattice parameter = 0.361 nm) tilt boundary (tilt angle = 5 degrees), estimate the 

spacing between dislocations? 

See complete solution here: https://www.iitdocs.com/2026/05/what-are-different-types-of-solid-solid.html

(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? 

See complete solution here: https://www.iitdocs.com/2026/05/what-are-different-types-of-solid-solid.html

For heterogeneous nucleation on the mould wall; what is the importance of the width of the crack at its mouth on the mould surface? Under what condition(s) crystalline metallic phase will not nucleate from liquid retained in a mold-wall crevice even much below Tm? Explain using schematic diagram

 2. For heterogeneous nucleation on the mould wall; what is the importance of the width of the 

crack at its mouth on the mould surface? Under what condition(s) crystalline metallic phase will 

not nucleate from liquid retained in a mold-wall crevice even much below Tm? Explain using 

schematic diagram ..

 Full Solution is here : https://www.iitdocs.com/2026/05/what-are-different-types-of-solid-solid.html

(a) For heterogeneous nucleation on the mould wall; what is the importance of the width of the 

crack at its mouth on the mould surface? Under what condition(s) crystalline metallic phase will 

not nucleate from liquid retained in a mold-wall crevice even much below Tm? Explain using 

schematic diagram. 2+2=4 

(b) Estimate the number of crystal-like clusters in 1 mm3

 of copper at its melting point for 

spherical clusters containing 100 atoms. Given: The atomic volume of liquid 

copper ()=1.6 x 10-29 m3

 , Solid -liquid interfacial energy (SL) = 0.177 J m-2 , Boltzmann 

constant (k) = 1.38 X 10-23 J K-1, Melting Temperature (TM) = 1356 K. 4 

[Hint: the number spherical clusters of radius r 

no= total number of atoms in the spherical cluster]. 

(c) The equilibrium shape of a coherent precipitate can be predicted by using -plot. How will 

you determine the equilibrium shape of an incoherent precipitate using strain energy? 2 

[Hint: Think and answer

What are different types of solid-solid interfaces? Mention them

 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

Visit this url for IIT Kanpur Materials Science and Eng. Course Materials Assignments, Quiz, Midsem, Endsem, Solutions,

IIT Kanpur Materials Science Course Materials | MSE302 MSE615 MSE616 MSE617 MSE626 MSE639 MSE651 MSE671 | Assignments, Quiz, Midsem, Endsem, Solutions,

 https://www.iitdocs.com/p/iit-kanpur-materials-science-course.html