3.22 Mechanical Behavior of materials PS8 Solution Due: April, 27, 2004 (Tuesday) before class (10:00am)
|
|
- Albert McCormick
- 5 years ago
- Views:
Transcription
1 3. Mechanical Behavior of materials PS8 Solution Due: April, 7, 004 (Tuesday before class (10:00am 8 1. Annealed copper have a dislocation density of approimately 10 cm. Calculate the total elastic strain energy for copper. Assume that the dislocations are screw dislocations for simplicity and dislocation core radius is r0 = 5b. Neglect the strain energy of the dislocation core. For copper G=40GPa and b=0.5nm. U el 9 Gb R Gb 1/ ρ (40 10 ( / L = ln ln = 4 r = π 0 4π 5b 4π = J / m Total strain energy is 1 ln 5 ( ( U el Total = = J / m.. An FCC single crystal of nickel is sheared by γ = Assuming that the dislocation density is equal to 10 8 cm - and that it remains constant, what is the average distance each dislocation will have to move? If the shear strain rate is 10-4 sec -1, what is the mean velocity of the dislocation? Assume that the Burgers vector of Ni is 0.5 nm. γ (i l = = = 4 10 m. ρ 1 9 b (10 ( (ii 4 γ 10 7 γ = ρbv. So v = = = 4 10 m / sec. ρ 1 b 10 ( The figure below shows the arrangement of atoms for a curved dislocation segment. The open circles represent the atomic planes just above the slip plane and the closed circles represent the atoms just below. (a What is the Burgers vector for the dislocation shown below? (b Indicate the regions of slipped material. (c Define the regions of the dislocation, whether screw, edge or mied. 1
2 y (d If the dislocation segment epands in its own plane under the influence of an applied stress, slip step will be formed when all components of the segment intersect the faces of the crystal. What will be the orientation of slip steps formed on the crystal faces assuming that shear stress ( τ = τ zy is applied along the y-direction?
3 Eplain in detail. I have labeled three corners P, Q, and R. With the application of a shear stress, τ, on the surface of the lattice, the dislocation will epand. The slip steps will be formed along PQ and parallel to QR. After time t T the slip step will encompass all of PQ with the top layer of atoms etending one bond length paralled to BC. 4. In rectangular coordinates, the stress field surrounding edge dislocation is given by y yy y = Gb π y(3 (1 v ( + y Gb = π y( (1 v ( + y Gb = π ( + y y (1 v ( + y zz = v + ( yy y For a single edge dislocations in a block of annealed pure copper, plot the stress field along the positive y-ais and eplain how your result relates to the need for a dislocation core. For =0, the stress becomes a function of y only. Gb 1 =, π (1 v y Gb 1 yy =, y = 0 π (1 v y 3
4 Normalizing by Gb / π (1 v For y=0, =0, stresses ehibit a singularity. Thus, we must analyze the stress away from the dislocation core. 5. (a Eplain why a second hardness measurement made adjacent to a previous measurement indicates a higher hardness. The previous hardness measurement leads to plastic deformation near the indented area. This plastically deformed region is thus work hardened. The work hardened area around the previous indentation results in a higher hardness when indented a second time. (b In class, we have shown how the motion of dislocations on the atomic scale results in macroscopic plastic deformation and ductility. How can we eplain brittle, crystalline solids such as ceramics that show essentially no plastic deformation? Can we conclude that ceramics have a perfect, dislocation free crystal structure? Brittle materials such as ceramics do have dislocations, but because of the stronger character of the ionic or covalent bonds in these materials, they are etremely difficult to move by glide through the lattice as we depicted in class. These materials typically fail by brittle fracture before stresses large enough to overcome the lattice resistance (opposing dislocation motion are attained. It should be noted that this is not true at high temperatures (where the lattice resistance goes down or if a large eternal pressure is imposed (fracture is suppressed by the high pressure. Under these conditions ceramics can actually show significant plasticity. 6. (a Maraging steels are relatively soft upon quenching from the austenitizing temperature range but strengthen greatly following eposure to a reheating treatment at intermediate temperature. Given that the carbon level of such steels is typically less than 4
5 0.03%, whereas the alloy contains additions of Ni, Mo, and Ti, speculate as to the probable strengthening mechanism that controls the strength of this class of alloys. Ferritic steels derive much of their strength from solid solution strengthening of carbon in the BCC lattice. In maraging steels, the carbon concentration is so low that the solid solution of carbon in the steel does not influence the strength of the steel significantly. If solid solution strengthening were present, then the steel would not be relatively soft after quenching from the austenitizing temperature. From the fact that strength increases following eposure to an intermediate temperature (aging after quenching, we can speculate that the strengthening comes from the precipitation of a second phase (NiMo and NiTi due to the presence of the alloying elements. Therefore, the probable strengthening mechanism in maraging steels is precipitation hardening. (b Eplain why metals show the ductile-brittle transition temperature behavior at low temperatures. The yield strength of metal decreases linearly with temperature and increases with ln γ. The plastic zone size, r p, of fracture sample depends on the yield strength. As temperature decreases, the yield strength of the metal increases and the size of plastic zone decreases. By suppressing the size of the plastic zone at low temperatures, the facture behavior of metal becomes more brittle. 7. At 5, an alloy yields at 170 MPa when strained at 0.0 s -1. The same alloy yields at 165 MPa when the strain rate decreased by a factor of ten and the temperature is kept the same. What test temperature would have to be used with a strain rate of 0.0sec -1 to reach a yield strength of 165 MPa? Assume that the energy per bond (Q b is 500 kj/mol. The yield strength of a material as a function of temperature and strain rate is kt γ 0 τ ( γ, T = τ ln. Q b γ Q b = 500 kj/mol = J/atom γ 0 τ (0.0, T = 98 = τ ln = 170MPa γ 0 τ (0.00, T = 98 = τ ln = 165MPa By solving the above equations, we have 5
6 51 1 γ = τ MPa 0 sec 0 = To find the temperature at which the yield strength is 165MPa for a strain rate of 0.0 s -1, T γ 0 τ (0.0, T = τ ln = 165MPa T=303.55K=
Strengthening Mechanisms
ME 254: Materials Engineering Chapter 7: Dislocations and Strengthening Mechanisms 1 st Semester 1435-1436 (Fall 2014) Dr. Hamad F. Alharbi, harbihf@ksu.edu.sa November 18, 2014 Outline DISLOCATIONS AND
More informationChapter 8. Deformation and Strengthening Mechanisms
Chapter 8 Deformation and Strengthening Mechanisms Chapter 8 Deformation Deformation and Strengthening Issues to Address... Why are dislocations observed primarily in metals and alloys? How are strength
More informationSTRENGTHENING MECHANISM IN METALS
Background Knowledge Yield Strength STRENGTHENING MECHANISM IN METALS Metals yield when dislocations start to move (slip). Yield means permanently change shape. Slip Systems Slip plane: the plane on which
More informationChapter Outline Dislocations and Strengthening Mechanisms. Introduction
Chapter Outline Dislocations and Strengthening Mechanisms What is happening in material during plastic deformation? Dislocations and Plastic Deformation Motion of dislocations in response to stress Slip
More informationChapter 7 Dislocations and Strengthening Mechanisms. Dr. Feras Fraige
Chapter 7 Dislocations and Strengthening Mechanisms Dr. Feras Fraige Chapter Outline Dislocations and Strengthening Mechanisms What is happening in material during plastic deformation? Dislocations and
More informationTutorial 2 : Crystalline Solid, Solidification, Crystal Defect and Diffusion
Tutorial 1 : Introduction and Atomic Bonding 1. Explain the difference between ionic and metallic bonding between atoms in engineering materials. 2. Show that the atomic packing factor for Face Centred
More informationChapter 8 Strain Hardening and Annealing
Chapter 8 Strain Hardening and Annealing This is a further application of our knowledge of plastic deformation and is an introduction to heat treatment. Part of this lecture is covered by Chapter 4 of
More informationLectures on: Introduction to and fundamentals of discrete dislocations and dislocation dynamics. Theoretical concepts and computational methods
Lectures on: Introduction to and fundamentals of discrete dislocations and dislocation dynamics. Theoretical concepts and computational methods Hussein M. Zbib School of Mechanical and Materials Engineering
More informationIMPERFECTIONSFOR BENEFIT. Sub-topics. Point defects Linear defects dislocations Plastic deformation through dislocations motion Surface
IMPERFECTIONSFOR BENEFIT Sub-topics 1 Point defects Linear defects dislocations Plastic deformation through dislocations motion Surface IDEAL STRENGTH Ideally, the strength of a material is the force necessary
More informationDislocations in Materials. Dislocations in Materials
Pose the following case scenario: Consider a block of crystalline material on which forces are applied. Top Force (111) parallel with top surface Bottom Force Sum Sum of of the the applied forces give
More informationCHAPTER 4 INTRODUCTION TO DISLOCATIONS. 4.1 A single crystal of copper yields under a shear stress of about 0.62 MPa. The shear modulus of
CHAPTER 4 INTRODUCTION TO DISLOCATIONS 4.1 A single crystal of copper yields under a shear stress of about 0.62 MPa. The shear modulus of copper is approximately. With this data, compute an approximate
More informationa. 50% fine pearlite, 12.5% bainite, 37.5% martensite. 590 C for 5 seconds, 350 C for 50 seconds, cool to room temperature.
Final Exam Wednesday, March 21, noon to 3:00 pm (160 points total) 1. TTT Diagrams A U.S. steel producer has four quench baths, used to quench plates of eutectoid steel to 700 C, 590 C, 350 C, and 22 C
More informationLecture # 11 References:
Lecture # 11 - Line defects (1-D) / Dislocations - Planer defects (2D) - Volume Defects - Burgers vector - Slip - Slip Systems in FCC crystals - Slip systems in HCP - Slip systems in BCC Dr.Haydar Al-Ethari
More informationDislocations & Materials Classes. Dislocation Motion. Dislocation Motion. Lectures 9 and 10
Lectures 9 and 10 Chapter 7: Dislocations & Strengthening Mechanisms Dislocations & Materials Classes Metals: Disl. motion easier. -non-directional bonding -close-packed directions for slip. electron cloud
More informationIntroduction to Engineering Materials ENGR2000 Chapter 7: Dislocations and Strengthening Mechanisms. Dr. Coates
Introduction to Engineering Materials ENGR2000 Chapter 7: Dislocations and Strengthening Mechanisms Dr. Coates An edge dislocation moves in response to an applied shear stress dislocation motion 7.1 Introduction
More informationA DISLOCATION MODEL FOR THE PLASTIC DEFORMATION OF FCC METALS AN ANALYSIS OF PURE COPPER AND AUSTENITIC STEEL
A DISLOCATION MODEL FOR THE PLASTIC DEFORMATION OF FCC METALS AN ANALYSIS OF PURE COPPER AND AUSTENITIC STEEL Background In the bcc model for work hardening in single phase materials, see (6), it is assumed
More informationStrengthening Mechanisms
Strengthening Mechanisms The ability of a metal/ alloy to plastically deform depends on the ability of dislocations to move. Strengthening techniques rely on restricting dislocation motion to render a
More informationME 254 MATERIALS ENGINEERING 1 st Semester 1431/ rd Mid-Term Exam (1 hr)
1 st Semester 1431/1432 3 rd Mid-Term Exam (1 hr) Question 1 a) Answer the following: 1. Do all metals have the same slip system? Why or why not? 2. For each of edge, screw and mixed dislocations, cite
More information3, MSE 791 Mechanical Properties of Nanostructured Materials
3, MSE 791 Mechanical Properties of Nanostructured Materials Module 3: Fundamental Physics and Materials Design Lecture 1 1. What is strain (work) hardening? What is the mechanism for strain hardening?
More information(a) Would you expect the element P to be a donor or an acceptor defect in Si?
MSE 200A Survey of Materials Science Fall, 2008 Problem Set No. 2 Problem 1: At high temperature Fe has the fcc structure (called austenite or γ-iron). Would you expect to find C atoms in the octahedral
More informationCHAPTER 8 DEFORMATION AND STRENGTHENING MECHANISMS PROBLEM SOLUTIONS
CHAPTER 8 DEFORMATION AND STRENGTHENING MECHANISMS PROBLEM SOLUTIONS Slip Systems 8.3 (a) Compare planar densities (Section 3.15 and Problem W3.46 [which appears on the book s Web site]) for the (100),
More informationME254: Materials Engineering Second Midterm Exam 1 st semester December 10, 2015 Time: 2 hrs
ME254: Materials Engineering Second Midterm Exam 1 st semester 1436-1437 December 10, 2015 Time: 2 hrs Problem 1: (24 points) A o = π/4*d o 2 = π/4*17 2 = 227 mm 2 L o = 32 mm a) Determine the following
More informationChapter 7: Dislocations and strengthening mechanisms. Strengthening by grain size reduction
Chapter 7: Dislocations and strengthening mechanisms Mechanisms of strengthening in metals Strengthening by grain size reduction Solid-solution strengthening Strain hardening Recovery, recrystallization,
More informationUNIVERSITY OF TORONTO FACULTY OF APPLIED SCIENCE AND ENGINEERING. FINAL EXAMINATION, April 17, 2017 DURATION: 2 hrs. First Year.
UNIVERSITY OF TORONTO FACULTY OF APPLIED SCIENCE AND ENGINEERING FINAL EXAMINATION, April 17, 2017 DURATION: 2 hrs First Year MSE160H1S - Molecules and Materials Exam Type: A Calculator type 3 Examiner
More informationE45 Midterm 01 Fall 2007! By the 0.2% offset method (shown on plot), YS = 500 MPa
1.!Mechanical Properties (20 points) Refer to the following stress-strain plot derived from a standard uniaxial tensile test of a high performance titanium alloy to answer the following questions. Show
More informationPlastic Deformation and Strengthening Mechanisms in Crystalline Materials
Plastic Deformation and Strengthening Mechanisms in Crystalline Materials Updated 6 October, 2011 Slip in Polycrystalline Materials and all you ll ever need to know about it in MSE250 and life (unless
More informationImperfections in atomic arrangements
MME131: Lecture 9 Imperfections in atomic arrangements Part 2: 1D 3D Defects A. K. M. B. Rashid Professor, Department of MME BUET, Dhaka Today s Topics Classifications and characteristics of 1D 3D defects
More informationMEMS 487. Class 04, Feb. 13, K.J. Hemker
MEMS 487 Class 04, Feb. 13, 2003 Materials Come As:!Amorphous Glasses, polymers, some metal alloys Processing can result in amorphous structures! Crystalline Single crystals Textured crystals Polycrystalline
More informationEngineering materials
1 Engineering materials Lecture 2 Imperfections and defects Response of materials to stress 2 Crystalline Imperfections (4.4) No crystal is perfect. Imperfections affect mechanical properties, chemical
More informationStudent Name: ID Number:
Student Name: ID Number: DEPARTMENT OF MECHANICAL ENGINEERING CONCORDIA UNIVERSITY MATERIALS SCIENCE - MECH 1/ - Sections T & X MIDTERM 003 Instructors: Dr. M.Pugh & Dr. M.Medraj Time Allowed: one (1)
More informationWhy are dislocations observed primarily in metals CHAPTER 8: DEFORMATION AND STRENGTHENING MECHANISMS
Why are dislocations observed primarily in metals CHAPTER 8: and alloys? DEFORMATION AND STRENGTHENING MECHANISMS How are strength and dislocation motion related? How do we manipulate properties? Strengthening
More informationProblems to the lecture Physical Metallurgy ( Materialkunde ) Chapter 6: Mechanical Properties
Institut für Metallkunde und Metallphysik Direktor: Prof. Dr. rer. nat. Günter Gottstein RWTH Aachen, D-52056 Aachen Internet: http://www.imm.rwth-aachen.de E-mail: imm@imm.rwth-aachen.de Tel.: +49 241
More information- Slip by dislocation movement - Deformation produced by motion of dislocations (Orowan s Eq.)
Lecture #12 - Critical resolved shear stress Dr. Haydar Al-Ethari - Slip y dislocation movement - Deformation produced y motion of dislocations (Orowan s Eq.) References: 1- Derek Hull, David Bacon, (2001),
More informationFundamentals of Plastic Deformation of Metals
We have finished chapters 1 5 of Callister s book. Now we will discuss chapter 10 of Callister s book Fundamentals of Plastic Deformation of Metals Chapter 10 of Callister s book 1 Elastic Deformation
More informationDefect in crystals. Primer in Materials Science Spring
Defect in crystals Primer in Materials Science Spring 2017 11.05.2017 1 Introduction The arrangement of the atoms in all materials contains imperfections which have profound effect on the behavior of the
More informationChapter 7: Dislocations and strengthening mechanisms
Chapter 7: Dislocations and strengthening mechanisms Introduction Basic concepts Characteristics of dislocations Slip systems Slip in single crystals Plastic deformation of polycrystalline materials Plastically
More informationStrengthening Mechanisms. Today s Topics
MME 131: Lecture 17 Strengthening Mechanisms Prof. A.K.M.B. Rashid Department of MME BUET, Dhaka Today s Topics Strengthening strategies: Grain strengthening Solid solution strengthening Work hardening
More informationبسم الله الرحمن الرحیم. Materials Science. Chapter 7 Mechanical Properties
بسم الله الرحمن الرحیم Materials Science Chapter 7 Mechanical Properties 1 Mechanical Properties Can be characterized using some quantities: 1. Strength, resistance of materials to (elastic+plastic) deformation;
More informationAERO 214. Introduction to Aerospace Mechanics of Materials. Lecture 2
AERO 214 Introduction to Aerospace Mechanics of Materials Lecture 2 Materials for Aerospace Structures Aluminum Titanium Composites: Ceramic Fiber-Reinforced Polymer Matrix Composites High Temperature
More informationImperfections in the Atomic and Ionic Arrangements
Objectives Introduce the three basic types of imperfections: point defects, line defects (or dislocations), and surface defects. Explore the nature and effects of different types of defects. Outline Point
More informationDeformation, plastic instability
Deformation, plastic instability and yield-limited design Engineering Materials 2189101 Department of Metallurgical Engineering Chulalongkorn University http://pioneer.netserv.chula.ac.th/~pchedtha/ Material
More informationPhase Transformations in Metals Tuesday, December 24, 2013 Dr. Mohammad Suliman Abuhaiba, PE 1
Ferrite - BCC Martensite - BCT Fe 3 C (cementite)- orthorhombic Austenite - FCC Chapter 10 Phase Transformations in Metals Tuesday, December 24, 2013 Dr. Mohammad Suliman Abuhaiba, PE 1 Why do we study
More informationCHAPTER 4 1/1/2016. Mechanical Properties of Metals - I. Processing of Metals - Casting. Hot Rolling of Steel. Casting (Cont..)
Processing of Metals - Casting CHAPTER 4 Mechanical Properties of Metals - I Most metals are first melted in a furnace. Alloying is done if required. Large ingots are then cast. Sheets and plates are then
More informationDislocations and Plastic Deformation
Dislocations and Plastic Deformation Edge and screw are the two fundamental dislocation types. In an edge dislocation, localized lattice distortion exists along the end of an extra half-plane of atoms,
More informationDuctility in steel reinforcement
Ductility in steel reinforcement Dr.Fahmida Gulshan Assistant Professor Department of Materials and Metallurgical Engineering Bangladesh University of Engineering and Technology Ductile and Brittle material
More informationMechanical Properties
Mechanical Properties Elastic deformation Plastic deformation Fracture II. Stable Plastic Deformation S s y For a typical ductile metal: I. Elastic deformation II. Stable plastic deformation III. Unstable
More informationEngineering Tripos Part IA Paper 2 - MATERIALS HANDOUT 4
Engineering Tripos Part IA Paper 2 - MATERIALS HANDOUT 4 First Year 6. Microstructure of Engineering Materials II 6.1 Atomic basis of Plasticity in Crystalline Materials 6.2 Manipulating Properties II:
More informationLecture # 11. Line defects (1D) / Dislocations
Lecture # 11 - Line defects (1-D) / Dislocations - Planer defects (2D) - Volume Defects - Burgers vector - Slip - Slip Systems in FCC crystals - Slip systems in HCP - Slip systems in BCC References: 1-
More informationThe Dislocation Basis of Yield and Creep
The Dislocation Basis of Yield and Creep David Roylance Department of Materials Science and Engineering Massachusetts Institute of Technology Cambridge, MA 02139 March 22, 2001 Introduction Phenomenological
More informationImperfections, Defects and Diffusion
Imperfections, Defects and Diffusion Lattice Defects Week5 Material Sciences and Engineering MatE271 1 Goals for the Unit I. Recognize various imperfections in crystals (Chapter 4) - Point imperfections
More informationMT 348 Outline No MECHANICAL PROPERTIES
MT 348 Outline No. 1 2009 MECHANICAL PROPERTIES I. Introduction A. Stresses and Strains, Normal and Shear Loading B. Elastic Behavior II. Stresses and Metal Failure A. ʺPrincipal Stressʺ Concept B. Plastic
More informationMovement of edge and screw dislocations
Movement of edge and screw dislocations Formation of a step on the surface of a crystal by motion of (a) n edge dislocation: the dislocation line moves in the direction of the applied shear stress τ. (b)
More informationA Comparison of Strain Deformation Mechanism of Al, Mo, MgO & CaO in Harper-Dorn Creep
Pak. j. eng. technol. sci. Volume 2, No 1, 2012, 27-38 ISSN: 2222-9930 print ISSN: 2224-2333 online A Comparison of Strain Deformation Mechanism of Al, Mo, MgO & CaO in Harper-Dorn Creep Mukhtar Ahmed
More informationTOPIC 2. STRUCTURE OF MATERIALS III
Universidad Carlos III de Madrid www.uc3m.es MATERIALS SCIENCE AND ENGINEERING TOPIC 2. STRUCTURE OF MATERIALS III Topic 2.3: Crystalline defects. Solid solutions. 1 PERFECT AND IMPERFECT CRYSTALS Perfect
More informationINSTITUTE OF AERONAUTICAL ENGINEERING (Autonomous) Dundigal, Hyderabad
INSTITUTE OF AERONAUTICAL ENGINEERING (Autonomous) Dundigal, Hyderabad -500 043 MECHANICAL ENGINEERING TUTORIAL QUESTION BANK Course Name METALLURGY AND MATERIAL SCIENCE Course Code AME005 Class III Semester
More informationPrecipitation Hardening. Outline. Precipitation Hardening. Precipitation Hardening
Outline Dispersion Strengthening Mechanical Properties of Steel Effect of Pearlite Particles impede dislocations. Things that slow down/hinder/impede dislocation movement will increase, y and TS And also
More informationImpurities in Solids. Crystal Electro- Element R% Structure negativity Valence
4-4 Impurities in Solids 4.4 In this problem we are asked to cite which of the elements listed form with Ni the three possible solid solution types. For complete substitutional solubility the following
More informationChapter 8: Deformation & Strengthening Mechanisms. School of Mechanical Engineering Choi, Hae-Jin ISSUES TO ADDRESS
Chapter 8: Deformation & Strengthening Mechanisms School of Mechanical Engineering Choi, Hae-Jin Materials Science - Prof. Choi, Hae-Jin Chapter 8-1 ISSUES TO ADDRESS Why are the number of dislocations
More informationMaterials and their structures
Materials and their structures 2.1 Introduction: The ability of materials to undergo forming by different techniques is dependent on their structure and properties. Behavior of materials depends on their
More informationASE324: Aerospace Materials Laboratory
ASE324: Aerospace Materials Laboratory Instructor: Rui Huang Dept of Aerospace Engineering and Engineering Mechanics The University of Texas at Austin Fall 2003 Lecture 3 September 4, 2003 Iron and Steels
More informationChapter 2. Ans: e (<100nm size materials are called nanomaterials)
Chapter 2 1. Materials science and engineering include (s) the study of: (a) metals (b) polymers (c) ceramics (d) composites (e) nanomaterials (f) all of the above Ans: f 2. Which one of the following
More informationSingle vs Polycrystals
WEEK FIVE This week, we will Learn theoretical strength of single crystals Learn metallic crystal structures Learn critical resolved shear stress Slip by dislocation movement Single vs Polycrystals Polycrystals
More informationPart IA Paper 2: Structures and Materials MATERIALS Examples Paper 3 Stiffness-limited Design; Plastic Deformation and Properties
Engineering Part IA Paper 2: Structures and Materials MATERIALS FIRST YEAR Examples Paper 3 Stiffness-limited Design; Plastic Deformation and Properties Straightforward questions are marked with a Tripos
More informationCME 300 Properties of Materials. ANSWERS Homework 2 September 28, 2011
CME 300 Properties of Materials ANSWERS Homework 2 September 28, 2011 1) Explain why metals are ductile and ceramics are brittle. Why are FCC metals ductile, HCP metals brittle and BCC metals tough? Planes
More informationModule 10. Crystal Defects in Metals I. Lecture 10. Crystal Defects in Metals I
Module 10 Crystal Defects in Metals I Lecture 10 Crystal Defects in Metals I 1 NPTEL Phase II : IIT Kharagpur : Prof. R. N. Ghosh, Dept of Metallurgical and Materials Engineering Introduction Keywords:
More informationHigh Temperature Materials. By Docent. N. Menad. Luleå University of Technology ( Sweden )
of Materials Course KGP003 Ch. 6 High Temperature Materials By Docent. N. Menad Dept. of Chemical Engineering and Geosciences Div. Of process metallurgy Luleå University of Technology ( Sweden ) Mohs scale
More information5. A round rod is subjected to an axial force of 10 kn. The diameter of the rod is 1 inch. The engineering stress is (a) MPa (b) 3.
The Avogadro's number = 6.02 10 23 1 lb = 4.45 N 1 nm = 10 Å = 10-9 m SE104 Structural Materials Sample Midterm Exam Multiple choice problems (2.5 points each) For each problem, choose one and only one
More informationQuestion Grade Maximum Grade Total 100
The Islamic University of Gaza Industrial Engineering Department Engineering Materials, EIND 3301 Final Exam Instructor: Dr. Mohammad Abuhaiba, P.E. Exam date: 31/12/2013 Final Exam (Open Book) Fall 2013
More informationKinetics - Heat Treatment
Kinetics - Heat Treatment Nonequilibrium Cooling All of the discussion up till now has been for slow cooling Many times, this is TOO slow, and unnecessary Nonequilibrium effects Phase changes at T other
More informationFracture. Brittle vs. Ductile Fracture Ductile materials more plastic deformation and energy absorption (toughness) before fracture.
1- Fracture Fracture: Separation of a body into pieces due to stress, at temperatures below the melting point. Steps in fracture: 1-Crack formation 2-Crack propagation There are two modes of fracture depending
More informationIntroduction to Materials Science
EPMA Powder Metallurgy Summer School 27 June 1 July 2016 Valencia, Spain Introduction to Materials Science Prof. Alberto Molinari University of Trento, Italy Some of the figures used in this presentation
More informationChapter 9: Dislocations & Strengthening Mechanisms. Why are the number of dislocations present greatest in metals?
Chapter 9: Dislocations & Strengthening Mechanisms ISSUES TO ADDRESS... Why are the number of dislocations present greatest in metals? How are strength and dislocation motion related? Why does heating
More informationHigh strength low alloy (HSLA).
7 Alloy Steels High strength low alloy (HSLA). a type of steel alloy that provides many benefits over regular steel alloys contain a very small percentage of carbon (less than one-tenth of a percent) and
More informationDept.of BME Materials Science Dr.Jenan S.Kashan 1st semester 2nd level. Imperfections in Solids
Why are defects important? Imperfections in Solids Defects have a profound impact on the various properties of materials: Production of advanced semiconductor devices require not only a rather perfect
More informationLecture 12: High Temperature Alloys
Part IB Materials Science & Metallurgy H. K. D. H. Bhadeshia Course A, Metals and Alloys Lecture 12: High Temperature Alloys Metallic materials capable of operating at ever increasing temperatures are
More informationEngineering 45: Properties of Materials Final Exam May 9, 2012 Name: Student ID number:
Engineering 45: Properties of Materials Final Exam May 9, 2012 Name: Student ID number: Instructions: Answer all questions and show your work. You will not receive partial credit unless you show your work.
More informationChapter 7: Mechanical Properties 1- Load 2- Deformation 3- Stress 4- Strain 5- Elastic behavior
-1-2 -3-4 ( ) -5 ( ) -6-7 -8-9 -10-11 -12 ( ) Chapter 7: Mechanical Properties 1- Load 2- Deformation 3- Stress 4- Strain 5- Elastic behavior 6- Plastic behavior 7- Uniaxial tensile load 8- Bi-axial tensile
More informationLearning Objectives. Chapter Outline. Solidification of Metals. Solidification of Metals
Learning Objectives Study the principles of solidification as they apply to pure metals. Examine the mechanisms by which solidification occurs. - Chapter Outline Importance of Solidification Nucleation
More informationCREEP CREEP. Mechanical Metallurgy George E Dieter McGraw-Hill Book Company, London (1988)
CREEP CREEP Mechanical Metallurgy George E Dieter McGraw-Hill Book Company, London (1988) Review If failure is considered as change in desired performance*- which could involve changes in properties and/or
More informationChapter Outline Mechanical Properties of Metals How do metals respond to external loads?
Chapter Outline Mechanical Properties of Metals How do metals respond to external loads?! Stress and Strain " Tension " Compression " Shear " Torsion! Elastic deformation! Plastic Deformation " Yield Strength
More informationHomework 4 on Dislocations, Yield Stress, Hardness, Creep, Grain Size
Homework 4 on Dislocations, Yield Stress, Hardness, Creep, Grain Size 27-301, A. D. Rollett, Fall 2002 Chemical processing plant sometimes uses nickel or nickel-based alloys because of their corrosion
More informationInstructor: Yuntian Zhu. Lecture 8
MSE 791: Mechanical Properties of Nanostructured Materials Module 3: Fundamental Physics and Materials Design Instructor: Yuntian Zhu Office: 308 RBII Ph: 513-0559 ytzhu@ncsu.edu Lecture 8 Deformation
More informationCHAPTER 6: MECHANICAL PROPERTIES ISSUES TO ADDRESS...
CHAPTER 6: MECHANICAL PROPERTIES ISSUES TO ADDRESS... Stress and strain: What are they and why are they used instead of load and deformation? Elastic behavior: When loads are small, how much deformation
More informationImperfections: Good or Bad? Structural imperfections (defects) Compositional imperfections (impurities)
Imperfections: Good or Bad? Structural imperfections (defects) Compositional imperfections (impurities) 1 Structural Imperfections A perfect crystal has the lowest internal energy E Above absolute zero
More informationContinuous Cooling Diagrams
Continuous Cooling Diagrams Isothermal transformation (TTT) diagrams are obtained by rapidly quenching to a given temperature and then measuring the volume fraction of the various constituents that form
More informationModule-6. Dislocations and Strengthening Mechanisms
Module-6 Dislocations and Strengthening Mechanisms Contents 1) Dislocations & Plastic deformation and Mechanisms of plastic deformation in metals 2) Strengthening mechanisms in metals 3) Recovery, Recrystallization
More informationMYTHS AND LEGENDS OF PROBE NEEDLES. Presented by Michelle Gesse Advanced Probing Systems, Inc.
MYTHS AND LEGENDS OF PROBE NEEDLES Presented by Michelle Gesse Advanced Probing Systems, Inc. 1 TRUE OR FALSE? Rhenium atoms are like small pebbles that fill in the gaps between the much larger tungsten
More informationUNIVERSITY OF CALIFORNIA College of Engineering Department of Materials Science and Engineering. Professor R. Gronsky Fall Semester 2000
UNIVERSITY OF CALIFORNIA College of Engineering Department of Materials Science and Engineering Professor R. Gronsk Fall Semester 2000 ENGINEERING 45 MIDTERM #1 NAME: (Please Print Clearl) This is a closed
More informationMaterials Science. Imperfections in Solids CHAPTER 5: IMPERFECTIONS IN SOLIDS. Types of Imperfections
In the Name of God Materials Science CHAPTER 5: IMPERFECTIONS IN SOLIDS ISSUES TO ADDRESS... What are the solidification mechanisms? What types of defects arise in solids? Can the number and type of defects
More informationPh.D. Admission 20XX-XX Semester X
Ph.D. Admission 20XX-XX Semester X Written Examination Materials Science & Engineering Department, IIT Kanpur Date of Examination: XX XXXX 20XX Timing: XX:XX XX:XX XX Application# Please read these instructions
More informationMaterials Issues in Fatigue and Fracture. 5.1 Fundamental Concepts 5.2 Ensuring Infinite Life 5.3 Failure 5.4 Summary
Materials Issues in Fatigue and Fracture 5.1 Fundamental Concepts 5.2 Ensuring Infinite Life 5.3 Failure 5.4 Summary 1 A simple view of fatigue 1. Will a crack nucleate? 2. Will it grow? 3. How fast will
More information=E Δ l l o. π d o 2 4. Δ l = 4Fl o π d o 2 E. = 0.50 mm (0.02 in.)
6.10 (a) This portion of the problem asks that the tangent modulus be determined for the gray cast iron, the stress-strain behavior of which is shown in Figure 6.25. The slope (i.e., σ/ ε) of a tangent
More informationChap. 7. Intersection of Dislocations
Chap. 7. Intersection of Dislocations Plastic Deformation of Crystal - Slip starts at a slip system having the largest Schmid factor. - A dislocation moving in slip plane will intersect other dislocations
More information(12) 1. Just one True and False question and a couple of multiple choice calculations, circle one answer for each problem, no partial credit.
(1) 1. Just one True and False question and a couple of multiple choice calculations, circle one answer for each problem, no partial credit. The next page is left blank for your use, but no partial will
More informationMechanical Properties
Stress-strain behavior of metals Elastic Deformation Plastic Deformation Ductility, Resilience and Toughness Hardness 108 Elastic Deformation bonds stretch δ return to initial Elastic means reversible!
More informationChapter 7. Stainless Steels. /MS371/ Structure and Properties of Engineering Alloys
Chapter 7 Stainless Steels Stainless steels at least % Cr in iron is required (max 30% Cr) Cr: to make iron surface by forming a surface oxide film protecting the underlying metal from corrosion Ni: to
More information4-Crystal Defects & Strengthening
4-Crystal Defects & Strengthening A perfect crystal, with every atom of the same type in the correct position, does not exist. The crystalline defects are not always bad! Adding alloying elements to a
More informationCrystal Defects. Perfect crystal - every atom of the same type in the correct equilibrium position (does not exist at T > 0 K)
Crystal Defects Perfect crystal - every atom of the same type in the correct equilibrium position (does not exist at T > 0 K) Real crystal - all crystals have some imperfections - defects, most atoms are
More informationMetal working: Deformation processing II. Metal working: Deformation processing II
Module 28 Metal working: Deformation processing II Lecture 28 Metal working: Deformation processing II 1 Keywords : Difference between cold & hot working, effect of macroscopic variables on deformation
More information