1
Seat No.: Enrolment
GUJARAT TECHNOLOGICAL UNIVERSITY
BE SEMESTER-VII(NEW) • EXAMINATION WINTER 2016
Subject Code:2173614 Date:21/11/2016
Subject Name:Refractories-II(Department Elective VIII)
Time: 10.30 AM to 1.00 PM Total Marks: 70
Instructions:
1. Attempt all questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
MARKS
Q.1
Short Questions
14
1
Write the formula of cordierite
2
Write the chemical composition of borosilicate glass
3
Write the formula of cementite
4
Write the formula of bainite.
5
Write the formula of martensite.
6
Write the formula of lepidolite
7
Give an example of eutectoid reaction.
8
Write the formula of
9
Define toughening of glass
10
Define homogeneous nucleation.
11
Why mullite is called congruently developed compound?
12
Why andalucite is favoured over other aluminosilicates?
13
What is the shortcoming of kyanite?
14
Where silimanite is found more in nature?
Q.2

What is meant by refractoriness under load of a material? Explain
03

Discuss the polymorphic transformation of zironia.
04

Explain transformation toughening of zirconia bodies.
07
OR

Explain silicate and Kinetic theory of glass formation
07
Q.3

Define sintering.
03

Describe driving energy for sintering.
04

Explain different types of sintering.
07
OR
Q.3

Explain Growth phenomena
03

Explain difference between nucleation and growth.
04

Explain the model of crystal growth with mathematical derivation
07
Q.4

Define steel
03

Explain different types of steel.
04

Explain the phase diagram of Fe- Fe3C
07
OR
Q.4

Define normal and inverse spinel.
03

Describe the occurrences of chrome ore.
04

Describe the structure of chrome ore in detail.
07
Q.5

Define different types of alumina.
03

Describe occurrences of alumina.
04

Describe synthesis of alumina by Bayer's process.
07
OR
Q.5

What are raw materials normally used in glass making?
03
2

Explain the parameters for raw material selection.
04

Explain the role of silica, soda ash and alumina in soda lime silica glass.
07