1. Write the Ms temperature equation. Calculate the Ms temperature for a carbon steel with

0.2C, 0.4 Si, 0.7Mn and for an alloy with 0.2C, 0.4Si, 0.7Mn, 1,0%Cr and 0.3%Mo.

2. What do you mean by white layer in nit riding process ?

3. What is the difference between harden ability and hardness.

4. What is need for sub zero treatment?

5. What are the application of carbonitriding?

6. Why we are not heat treating ferritic stainless steels.

7. Why the carbon content is restricted to 6.67% in the Iron-Carbon diagram.

8. Why we are not heating the hyper eutectoid steels above the upper critical temperature for

annealing.

9. Draw the microstructure of a 0.4% carbon steel

(a) Annealed (b) Normalized and (c) Hardened condition.

10. Why we are not hardening mild steel.

PART - B (5 X 16 = 80 Marks)

11. (a) Discuss in detail the mechanism of pearlitic and bainitic

transformation. (8)

(b) How to develop the TTT diagram. Draw the TTT diagram for an

eutectoid steel and explain the various factors affecting it. (8)

12.(a) Discuss in detail the heat treatment temperature, holding time,

microstructural changes for annealing, normalising, hardening

and tempering for a 0.2% carbon steel, 0.8% carbon steel,

1.2% carbon steel. (16)

( OR )

(b) Discuss briefly Jominy End quench test and hardenability testing

based on ASTM Number and chemical composition. (16)

13. (a) (i) Give a detailed account of gas carburizing. (8)

(ii) Explain in detail different methods of Nitriding and give the

advantages and limitations. (8)

( OR )

(b) (i) Discuss in detail silionising, chronising and boronising processes. (8)

(ii) Explain flame hardening and induction hardening with neat

sketches. (8)

14. (a) (i) Give a detailed account of various quenching media's used and

their characteristics (8)

(ii) Give a detailed account of various types of furnace atmospheres. (8)

( OR )

(b) (i) List the various types of heat treatment furnaces and explain the

working of fluidised bed heat treatment furnace. (8)

(ii) Discuss in detail about temperature control in heat treatment

furnaces. (8)

15. (a)(i) Explain in detail heat treatment of white cast iron and grey cast iron. (8)

(ii)Give the typical heat treatment for a high speed tool steep and

explain the different steps. (8)

( OR )

(b)(i) Discuss in detail precipitation hardening of an aluminium copper alloy.(8)

(ii) List the various defects normally observed in heat treated parts and

discuss the causes and remedies for any four such defects. (8)

Answer ALL questions.

PART A — (10 ´ 2 = 20 marks)

1. Define Fracture Toughness.

2. What is Arrhenius equation? What are its uses?

3. Give two examples for precipitation hardenable steels.

4. Show the relationship between critical stress intensity factor KIC and thickness of the

material.

5. Why heterogeneous nucleation occurs more readily than homogeneous nucleation?

6. What is the effect of applied stress on martensite formation?

7. What are the essential conditions for precipitation hardening?

8. What is low cycle fatigue? Give two examples where this is significant.

9. State the factors that influence creep rate in metals.

10. What are the different types of martensites in steels?

PART B — (5 ´ 16 = 80 marks)

11. (i) What are the steps in precipitation hardening? (6)

(ii) Explain the mechanism and stages in the strengthening of alloys by precipitation

hardening with a suitable example. (6)

(iii) Compare dispersion strengthening and precipitation strengthening. Give one example for

each. (4)

(a) (i) Derive an expression for the critical free energy change of a spherical particle

homogeneously nucleating from the melt. (10)

(ii) Discuss how the activation energy for a reaction can be determined graphically. (6)

Or

(b) (i) Discuss the mechanism of pearlite formation in steels. (8)

(ii) Discuss uphill diffusion with suitable examples. (8)

(a) (i) What are the characteristics of martensitic transformation? Discuss with reference to

steels. (10)

(ii) Discuss briefly martensitic transformation in non–ferrous alloys. (6)

Or

(b) (i) What is shape memory effect in alloys? Give two examples and applications for shape

memory alloys. (10)

(ii) What is thermoelastic martensite? (6)

12. (a) (i) Discuss strengthening of metal by grain size control. (8)

(ii) What are the factors that can control the grain size of steels? (8)

Or

(b) What are the different modes of fracture? Explain stress intensity factor. Discuss the

factors that influence fracture toughness. (16)

13. (a) State Griffith's theory of brittle fracture and derive the Griffith's equation. Explain

Orowan's modification suggested to Griffith's equation.

(16)

Or

(b) (i) Explain low cycle fatigue and high cycle fatigue with the use of Coffin–Manson law

and Basquin's law. (10)

(ii) Discuss the mechanism of creep failure in metals. (6)

1. (a) Name and discuss atleast four important metallic properties?

(b) What causes metals to show alloying behavior? [8+8]

2. (a) Differentiate between a single crystal and polycrystalline material?

(b) Explain why fine grained materials have superior properties than coarse grained

materials?

(c) Explain the purpose of etching in metallographic examination? [6+6+4]

3. (a) Write short notes on:

i. Austenite

ii. Alpha ferrite

iii. Delta ferrite

iv. Cementite

(b) Write the allotropy nature of iron with temperature and also explain the effect of pressure

on allotropy of iron? [8+8]

4. (a) Write in detail about hot working tool steels and cold working tool steels?

(b) Write in detail about nickel steels? [8+8]

5. (a) Carburized components are subjected to subsequent hardening heat treatment.

However, nitrided articles will not be heat treated subsequently. Explain why?

(b) What is chemical heat treatment? Explain how it is done? What are the properties of

cyamided case? [6+10]

6. Discuss the following alloys:

(a) Cupronickels

(b) Beryllium Bronzes. [8+8]

7. (a) Briefly explain few mechanical properties of ceramic materials. Also describe how the

strength of the glass can be increased.

(b) Discuss briefly glass forming. [10+6]

8. (a) What is the purpose of reinforcements? Describe different types of reinforcements in

composites.

(b) Suggest an appropriate matrix to be used for the following fiber types with proper

instification:

i. SiC,

ii. Polyethylene

iii. E-glass. [10+6]

1. (a) The distance between (111) plane in FCC crystal is 2A0. Find out lattice parameter and

atomic diameter?

(b) Describe briefly miller bravais indices?

(c) Distinguish between space lattice and crystal structure?

(d) Give the relation between lattice parameter ‗a‘ and atomic radius ‗r‘ for simple cubic,

BCC, FCC and HCP with examples? [4+4+4+4]

2. (a) What are intermediate phases? Discuss various types of intermediate phases?

(b) What is the importance of ratio of radius of interstitial to solvent atom in interstitial

compounds? [8+8]

3. (a) Explain the procedure of preparation of steel samples for metallographic examination?

(b) Under Microscope grain boundaries appear black. Why?

(c) Ferrite and Cementite both etch white but their mixture pearlite normally appears as black

and white plates. Why? [8+4+4]

4. (a) Give the typical composition of white cast iron?

(b) Explain the malleabilizing treatment given to white cast Iron with a neat sketch?

(c) Explain the composition, microstructure and properties of gray cast Iron?[2+7+7]

5. (a) Distinguish between an alloy and a solid solution.

(b) Compare and contrast annealing and normalizing treatments. [4+12]

6. (a) Distinguish between manganese bronze and aluminium bronze. Mention their

properties and uses.

(b) Discuss briefly:

i. 70:30 Brass and

ii. Muntz metal. [8+8]

7. (a) In a heterogeneous multiphase refractory, what are the microstructural features present?

Mention their applications.

(b) Why chemically synthesized magnesium-aluminate spinel is used exclusively as

refractory in molten salt electrolysis cell for producing magnesium? [10+6]

8. (a) What are the characteristics of Al-MMC-continuous filament? Mention their

applications.

(b) Describe briefly any two important methods of component manufacture of composites.

[6+10]

1. Write a short note on

(a) Nucleation and growth

(b) Micro segregation and macro segregation

(c) Homogeneous and Heterogeneous nucleation

(d) Directional solidification. [4+4+4+4]

2. (a) Why is an octahedral void called Octahedral?

(b) Draw a unit cell of FCC and also show atleast one octahedral void in it. How

many such voids are present in it?

(c) Draw a unit cell of BCC and show atleast one octahedral void in it. How

many such voids are present in it?

(d) Draw a unit cell of HCP. Show one of the octahedral holes in it. How many

octahedral holes are present in it? [4+4+4+4]

3. Duralumin alloy rivets used in aircraft construction are kept at -400C after solution

treatment. Whenever required they are taken out and riveted on the spot. Explain

the reason for keeping them at -400C and also explain how rivets operation at room

temperature strengthen the rivets? [16]

4. (a) Give the classification of stainless steels?

(b) Explain each type of steel with chemical composition, microstructure, proper-

ties and applications? [4+12]

5. (a) What is Martensite? Distinguish between Lath Martensite and Accicular

martensite.

(b) Discuss briefly Nitriding of steels. [8+8]

6. Discuss the following alloys:

(a) Cupronickels

(b) Beryllium Bronzes. [8+8]

7. (a) Compare the properties of crystalline ceramics and glass ceramics.

(b) Why annealing and tempering operations are performed on glass? Describe.

8. (a) What is the role of matrix in a composite material? Discuss various types

matrix materials.

(b) Indicate any one important metal matrix composite and mention its charac-

teristics, properties and applications.

1. (a) Define grain and grain boundary? How does the presence of grain boundary

affect the physical and mechanical properties of metals?

(b) What is the effect of heating rate and cooling rate of steel on grain growth

and properties of steel?( Consider heating to Austenite zone and cooling from

the same zone)? [8+8]

2. (a) What are intermediate phases? Discuss various types of intermediate phases?

(b) What is the importance of ratio of radius of interstitial to solvent atom in

interstitial compounds? [8+8]

3. (a) Discuss the effect of alloying elements in Fe-Fe3C diagram?

(b) Discuss the effect of carbon on

i. Mechanical properties

ii. Grain size. [8+8]

4. (a) Give the heat treatment and applications for the following steels

i. Austenitic stainless steels

ii. Martensitic stainless steels

iii. Ferritic stainless steels

iv. Precipitation hardening stainless steels.

(b) Explain each type of steel with chemical composition, microstructure, proper-

ties and applications? [16]

5. (a) What is the difference between Iron-Cementite and Iron-graphite phase dia-

gram?

(b) Draw T-T-T diagram for a eutectoid steel and explain the effect of cooling

rate on the transformation products and hardness obtained. [6+10]

6. (a) Differentiate between oxygen free high conductivity copper and electrolytic

tough pitch copper. Indicate their relative conductivities.

(b) For any three important brasses, give composition, treatment, structure, prop-

erties and applications. [4+12]

7. Discuss the effect of the following factors on mechanical behaviour of ceramic ma-

terials:

(a) grain size and shape

(b) Purity and

(c) Porosity [8+4+4]

8. (a) What are laminates? Indicate their characteristics.

(b) Compare and contrast carbon matrices with glass matrices.

1. (a) Define crystallization of metal? How is that commercial alloy invariably so-

lidify with heterogeneous nucleation?

(b) What factor favours the formation of fine grained material? How is a large

single crystal being produced? [8+8]

2. (a) Discuss in detail the necessity of alloying with few examples.

(b) Explain how are alloys actually made in industry? [8+8]

3. (a) Define cast irons ? Explain the cooling history of 4.3% C in Fe-Fe3C system

by drawing cooling curve?

(b) Calculate proportionate of different phases for 2.8%C in Fe-Fe3C diagram at

12000C, 11730C, and 6000C. Also draw the microstructures at room tempera-

ture? [6+10]

4. (a) Why stainless steels are stainless?

(b) Is it possible to harden 18%Cr-8%Ni steels by heat treatment?

(c) Why Austenitic stainless steels prone to welddecay? How can you avoid weld

decay? [2+7+7]

5. (a) Distinguish between hardness and hardenability.

(b) Critically discuss Pack carburizing of steels. [5+11]

6. (a) What are light metals? Explain the important characteristics of aluminium

and its alloys.

(b) Describe alloy and temper designation of Al and its alloys. [8+8]

7. (a) Calculate the density of FeO which has an NaCl-type structure. (assume

stoichiometry). Radius of Iron is 0.74A0 & oxygen is 1.40 A0.

(b) Discuss briefly the structure, properties and uses of Al2O3. [6+10]

8. (a) Explain how to improve damping ability of a composite.

(b) Compare and contrast whisker and particulate reinforced composites.

1. (a) What is the importance of grain size in steel? How do you determine grain

size of the given steel?

(b) Explain why grains are stronger than grain boundaries at high temperature

and grain boundaries are stronger than grains at room temperatures? [8+8]

2. (a) Distinguish between commercially pure metal and an alloy?

(b) What is a master alloy? What are its chief characteristics?

(c) Justify the statement ― Alloy is a material which is expected of a metal, but

it is not a pure metallic element‖. [6+6+4]

3. (a) Name possible types of Cementite in Fe-Fe3C diagram? Explain why

proeu-

tectiod product forms at grain boundaries of austenite ?

(b) Differentiate between

i. Proeutectiod ferrite and eutectoid ferrite

ii. Hypoeutectic and Hyper eutectic white cast iron. [8+8]

4. What are four basic types of cast Irons? Explain them with respect to

properties,

microstructure with a diagram and applications? [16]

5. (a) What is an alloy? Give two examples.

(b) Discuss in detail the effect of alloying elements in steels.

[4+12]

6. (a) Alpha brasses are cold worked while Alpha-Beta brasses are hot worked.

Ex-

plain.

(b) Extensive coring occurs in cast bronzes compared to cast brasses. Give

rea-

sons.

(c) What is dezincification? What are its effects? How is it prevented?

[7+4+5]

7. (a) In a heterogeneous multiphase refractory, what are the microstructural

fea-

tures present? Mention their applications.

(b) Why chemically synthesized magnesium-aluminate spinel is used

exclusively

as refractory in molten salt electrolysis cell for producing magnesium? [10+6]

8. (a) What is aspect ratio? Why is it so important?

(b) Discuss briefly about whisker reinforced composites?

PART A — (10 ´ 2 = 20 marks)

1. Define Strain Hardening.

2. Compare edge and screw dislocation.

3. Sketch a tensile test specimen showing all dimensions in mm.

4. What type of grips are provided in a torsion testing machine to fix the specimen?

5. List out the different types of Hardness testing machines.

6. What property of metal does the impact test measure? Give its significance.

7. What is true stress? How to determine the same?

8. Define Endurance limit.

9. Sketch and mark the various stages in creep.

10. What are the four basic variables involved in creep tests?

PART B — (5 ´ 16 = 80 marks)

11. Explain different types of fatigue stress cycle, stresses and ratios.

12. (a) Explain strengthening mechanism due to dislocations with neat sketches.

Or

(b) List out the types of deformations in metals. With a neat sketch explain any one type of

plastic deformation.

13. (a) State the working principle of the machine used for tension test. What care should be

taken while performing a test on UTM?

Or

(b) State the importance of torque–twist curve and explain how to determine modulus of

rigidity from torque–twist curve.

14. (a) Explain the working principles of machines used to conduct Charpy and Izod impact

test. How specimens are put–up in both the tests? Why?

Or

(b) Discuss the factors considered for selection of hardness testing machine. What care must

be taken while selecting specimens for hardness test.

15. (a) Define fracture. Explain the types of fracture. Which type of fracture is preferable?

Why?

Or

(b) Discuss the following :

(i) Notch effects on fracture

(ii) Stages in the formation of ductile fracture.

——————

1.a) Explain the factors influencing critical cooling rate. Explain hardenability of steel.

b) Describe two different methods of obtaining spheroidized cementite structure?

2.a) Draw I-T diagram of 1080 steel and show a cooling curve that will result in a structure

of

(i)50% pearlite + 50% Mrtensite (ii)uniform pearlitic structure of Rc 40

(iii)100% Martensite (iv)100% coarse pearlite(v)100% fine pearlite.

b) Explain the residual stresses setup during handening. What is the purpose of deep freezing.

3.a) Explain temper brittleness in steels and suggest remedy?

b) What are the advantages and limitations of austempering?

c) Explain heat treatment to be given after carburising.

4.a) Describe precipitation hardening treatment. Differentiate between coherent and

incoherent precipitates.

b) What is the purpose of addition of alloying elements to the steels?

c) What is the effect of alloying elements upon Iron-Iron carbide diagram?

5. Write short notes on any THREE of the following:

a)Precipitation hardening stainless steels (b) HSLA steels ©Maraging steel

c)Heat resisting steels (d) High speed tool steel.

6. Explain Malleablising treatment. Explain structure, properties and applications of Ni-hard

and S.G.Iron.

7. Briefly write on any THREE of the following :

a) Muntz metal (b) Al-Li alloys (c) Titanium alloys

d) Nickel based super alloys (e) Babbits

8.a) Explain heat treatment, properties and applications of Ti-6Al – 4V alloy?

b) Explain the control of heat treatment atmospheres. What are the difficulties

involved in vacuum heat treatment