(SEM IV) THEORY EXAMINATION 2023-24 MATERIAL SCIENCE

This document is a B.Tech (Semester IV) Theory Examination Question Paper for the subject BOE403H – Material Science, conducted in the academic session 2023–2024.
It is a 3-hour, 70-mark examination aimed at evaluating students’ understanding of crystal structures, phase diagrams, diffusion, mechanical behavior of materials, magnetic & dielectric properties, creep, fatigue, composites, nanomaterials, and alloy transformations.

The paper is structured into three major sections—A, B, and C—progressing from fundamental definitions to analytical explanations and diagram-based applications.

SECTION A – Short Answer Questions (14 Marks)

Seven questions (2 marks each) covering essential foundational concepts:

Definitions of solidus, liquidus, and tie line in phase diagrams

Gibbs phase rule and its significance                                       Meaning of creep

Concept of critical cooling rate in heat treatment                  Slip vs Twinning mechanisms

Difference between diamagnetism and ferromagnetism      Definition of nanomaterials

This section tests conceptual clarity in basic material science phenomena.
(Questions available in both English and Hindi, indicating bilingual exam format.)

SECTION B – Descriptive / Analytical Questions (21 Marks)

Students must attempt any three of the following:

a. Hume-Rothery Rules & Solid Solutions

Explains formation of substitutional solid solutions based on atomic size, valency, crystal structure, and electronegativity.
Defines solid solution and distinguishes between interstitial and substitutional types.

b. Fick’s Laws of Diffusion

Describes:

Fick’s First Law for steady-state diffusion

Fick’s Second Law for non-steady-state diffusion and its derivation.

c. Fatigue Failure & S–N Curve

Defines fatigue, causes of cyclic stress failure, and explains the S–N curve characteristics for steel.

d. Insulating, Ferroelectric, and Superconducting Materials

Discusses properties such as high resistivity, polarization, Curie temperature, zero resistivity, Meissner effect, etc.

e. FRP Composites (Matrix & Reinforcement Role)

Detailed explanation of functions of matrix phase and reinforcement phase in Fiber Reinforced Polymer (FRP) composites.

This section evaluates deeper reasoning and engineering understanding.

SECTION C – Long Answer / Diagram-Based Questions (35 Marks Total)

Each numbered question offers two options; the student must attempt one option from each.

3. Phase Transformations / Lever Rule (7 Marks)

Option (a)
Describe and diagrammatically explain:

Eutectic reaction              Eutectoid reaction

Peritectic reaction           Peritectoid reaction

Option (b)
Process of constructing a binary phase diagram and derivation of the phase lever rule.

4. Iron–Iron Carbide Diagram / TTT Diagram (7 Marks)

Option (a)
Draw complete Fe–Fe₃C (Iron–Iron Carbide) diagram and discuss microstructures such as: ferrite, austenite, pearlite, cementite, bainite, martensite with invariant reactions.

Option (b)
Sketch TTT (Time–Temperature–Transformation) diagram and explain austenite transformation into:

Pearlite                       Bainite                       Martensite

5. Creep Curve / Stress–Strain Curve (7 Marks)

Option (a)
Explain primary, secondary, and tertiary creep using creep curve.

Option (b)
Draw and explain stress–strain curves for:

Ductile materials

Brittle materials
Discuss elastic region, yield point, UTS, fracture behavior.

6. Ferromagnetic Domain Theory / Dielectric Polarization (7 Marks)

Option (a)
Explain Domain Theory of Ferromagnetism: domains, domain walls, magnetization process.

Option (b)
Explain polarization mechanisms in dielectric materials:

Electronic                Ionic                      Dipolar                    Space charge polarization

7. Carbon Nanotubes / Smart Materials (7 Marks)

Option (a)
Discuss properties and applications of carbon nanotubes (CNTs)—mechanical strength, conductivity, thermal behavior, nanocomposites.

Option (b)
Write short notes on:

NiTi Alloy (Nitinol—shape memory alloy)                Shape Memory Effect

Metallic Glasses

Overall Purpose of the Document

This exam paper evaluates a student’s ability to:

Interpret phase diagrams and phase transformations

Understand diffusion, heat treatment, and microstructural evolution

Analyze mechanical behavior such as creep and fatigue

Understand magnetic and dielectric material behavior

Discuss advanced material systems (superconductors, ferroelectrics, nanomaterials)

Apply knowledge of composites and smart materials

Draw and interpret engineering diagrams (Fe–Fe₃C, TTT, stress–strain, creep curve)

It includes definitions, derivations, diagrams, microstructure interpretations, and advanced engineering analysis, making it a complete assessment of Material Science knowledge.