mse 527 l.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
MSE 527 PowerPoint Presentation
Download Presentation
MSE 527

Loading in 2 Seconds...

play fullscreen
1 / 42

MSE 527 - PowerPoint PPT Presentation


  • 254 Views
  • Uploaded on

MSE 527 . Fall 2011. MSE 527- Mechanical Behavior of Materials Time: Wed 18:30-19:50 PM, Room JD1504 Lecture units: 2.0, Lab design units: 1.0

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'MSE 527' - Jims


Download Now An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
mse 527

MSE 527

Fall 2011

slide2

MSE 527- Mechanical Behavior of Materials

Time: Wed 18:30-19:50 PM, Room JD1504

Lecture units: 2.0, Lab design units: 1.0

A survey of relationships between mechanical behavior and materials structure. Elements of creep, fracture and fatigue of metals, ceramics, and composites. Introduction to applied fracture mechanics and environmentally assisted cracking laboratory methods for evaluating structural property relationships, fracture toughness measurements and failure analysis using Scanning Electron Microscopy.

Textbook: R. W. Hertzberg, Deformation and Fracture Mechanics of Engineering Materials,

4th Ed., J. Wiley & Sons, 1996.

Instructor: Dr. Behzad Bavarian

Dept. of Manufacturing Systems Engineering and Management

Office: JD3513, 818/677-3917

Email: bavarian@csun.edu

Office Hour: W 5:30-6:15PM

Course Description:

Prerequisites: MSE 227 and MSE 227L

The main techniques used in this course, center around the application of scientific principles to real-life situations. Library research is necessary to develop most of the topic discussions. The course covers dislocation theory and plastic deformation in order to explain strengthening mechanisms in different materials. Materials applications in elevated temperature are studied to understand the design criteria for these applications.

Fundamentals of fracture mechanics, microstructure aspects of fracture toughness, transition temperature, environment-assisted cracking, and fatigue crack propagation is discussed to be able to design based on the damage tolerant concept, and failure analysis using scanning electron microscopy.

This course requires extensive design problem solving, technical presentation, and a term paper on a current topic in materials application or design.

slide4
Course Method and Expectations:

The main techniques to be used in this course, center on the application of scientific principles to real-life situations. Library research is necessary to develop most of the topic discussions.

Grading Policy

Homework 10%

Mid-term Exam 30%

Term project 15%

Final Exam 45%

Grading System:

Letter Grades Grade Points

A Outstanding 4.0

B Excellent 3.0

C Acceptable 2.0

D Passing 1.0

F Failure 0.0

Plus/Minus Grading

Last day to drop: Friday, Sept. 16, 2011

References:

1. D. Callister, Jr. Fundamentals of Materials Science and Engineering, J. Wiley & Sons, NY, 2nd Ed. 2005.

2. G. E. Dieter, Mechanical Metallurgy, McGraw-Hill, NY, 1994.

3. V. J. Colangelo and F.A. Meiser, Analysis of Metallurgical Failures, J. Wiley & Sons, NY, 1987.

4. ASM Metals Handbook, Volume 11, Failure Analysis and Prevention, Metals Park, 1986.

5. R. M. Caddell, Deformation and Fracture of Solids, 1980.

6. A. G. Guy, Elements of Physical Metallurgy, 1984.

slide5
Materials science deals with basic knowledge about the internal structure, properties and processing of materials.

Materials engineering deals with the application of knowledge gained by materials science to convert materials to products.

Materials Science and

Engineering

Materials Science

Materials Engineering

Basic Knowledge

of

Materials

Applied

Knowledge

of Materials

Resultant

Knowledge

of Structure and

Properties

1-4

types of materials
Types of Materials
  • Metallic Materials
        • Composed of one or more metallic elements.
          • Example:- Iron, Copper, Aluminum.
        • Metallic element may combine with nonmetallic elements.
          • Example:- Silicon Carbide, Iron Oxide.
        • Inorganic and have crystalline structure.
        • Good thermal and electric conductors.

Metals and Alloys

Ferrous

Eg: Steel,

Cast Iron

Nonferrous

Eg:Copper

Aluminum

1-5

types of materials7
Types of Materials
  • Polymeric (Plastic) Materials
        • Organic giant molecules and mostly noncrystalline.
        • Some are mixtures of crystalline and noncrystalline regions.
        • Poor conductors of electricity and hence used as insulators.
        • Strength and ductility vary greatly.
        • Low densities and decomposition temperatures.
        • Examples :- Poly vinyl Chloride (PVC), Polyester.
        • Applications:- Appliances, DVDs, Fabrics etc.

1-6

types of materials8
Types of Materials
  • Ceramic Materials
        • Metallic and nonmetallic elements are chemically bonded together.
        • Inorganic but can be either crystalline, noncrystalline or mixture of both.
        • High hardness, strength and wear resistance.
        • Very good insulator. Hence used for furnace lining for heat treating and melting metals.
        • Also used in space shuttle to insulate it during exit and reentry into atmosphere.
        • Other applications : Abrasives, construction materials, utensils etc.
        • Example:- Porcelain, Glass, Silicon nitride.

1-7

types of materials9
Types of Materials
  • Composite Materials
        • Mixture of two or more materials.
        • Consists of a filler material and a binding material.
        • Materials only bond, will not dissolve in each other.
        • Mainly two types :-
          • Fibrous: Fibers in a matrix
          • Particulate: Particles in a matrix
          • Matrix can be metals, ceramic or polymer
        • Examples :-
          • Fiber Glass ( Reinforcing material in a polyester or epoxy matrix)
          • Concrete ( Gravels or steel rods reinforced in cement and sand)
        • Applications:- Aircraft wings and engine, construction.

1-8

types of materials10
Types of Materials
  • Electronic Materials
      • Not Major by volume but very important.
      • Silicon is a common electronic material.
      • Its electrical characteristics are changed by adding impurities.
      • Examples:- Silicon chips, transistors
      • Applications :- Computers, Integrated Circuits, Satellites etc.

1-9

future trends
Future Trends
  • Metallic Materials
      • Production follows US economy closely.
      • Alloys may be improved by better chemistry and process control.
      • New aerospace alloys being constantly researched.
          • Aim: To improve temperature and corrosion resistance.
          • Example: Nickel based high temperature super alloys.
      • New processing techniques are investigated.
          • Aim: To improve product life and fatigue properties.
          • Example: Isothermal forging, Powder metallurgy.
      • Metals for biomedical applications

1-11

future trends12
Future Trends
  • Polymeric (Plastic Materials)
      • Fastest growing basic material (9% per year).
      • After 1995 growth rate decreased due to saturation.
      • Different polymeric materials can be blend together to produce new plastic alloys.
      • Search for new plastic continues.

1-12

future trends13
Future Trends
  • Ceramic Materials
      • New family of engineering ceramics are produced last decade
      • New materials and applications are constantly found.
      • Now used in Auto and Biomedical applications.
      • Processing of ceramics is expensive.
      • Easily damaged as they are highly brittle.
      • Better processing techniques and high-impact ceramics are to be found.

1-13

future trends14
Future Trends
  • Composite Materials
      • Fiber reinforced plastics are primary products.
      • On an average 3% annual growth from 1981 to 1987.
      • Annual growth rate of 5% is predicted for new composites such as Fiberglass-Epoxy and Graphite-Epoxy combinations.
      • Commercial aircrafts are expected to use more and more composite materials.

1-14

future trends15
Future Trends
  • Electronic Materials
      • Use of electronic materials such as silicon increased rapidly from 1970.
      • Electronic materials are expected to play vital role in “Factories of Future”.
      • Use of computers and robots will increase resulting in extensive growth in use of electronic materials.
      • Aluminum for interconnections in integrated circuits might be replaced by copper resulting in better conductivity.

1-15

future trends16
Future Trends
  • Smart Materials :Change their properties by sensing external stimulus.
    • Shape memory alloys: Strained material reverts back to its original shape above a critical temperature.
      • Used in heart valves and to expand arteries.
    • Piezoelectric materials: Produce electric field when exposed to force and vice versa.
      • Used in actuators and vibration reducers.
mems and nanomaterials
MEMS and Nanomaterials
  • MEMS: Microelectromechanical systems.
      • Miniature devices
      • Micro-pumps, sensors
  • Nanomaterials:Characteristic length < 100 nm
      • Examples: ceramics powder and grain size < 100 nm
      • Nanomaterials are harder and stronger than bulk materials.
      • Have biocompatible characteristics ( as in Zirconia)
      • Transistors and diodes are developed on a nanowire.
summary bonding
SUMMARY: BONDING

Type

Bond Energy

Comments

Ionic

Large!

Nondirectional (ceramics)

Variable

Directional

Covalent

large-Diamond

semiconductors, ceramics

small-Bismuth

polymer chains)

Variable

Metallic

large-Tungsten

Nondirectional (metals)

small-Mercury

Directional

inter-chain (polymer)

Secondary

smallest

inter-molecular

14

face centered cubic structure fcc
FACE CENTERED CUBIC STRUCTURE (FCC)

• Close packed directions are face diagonals.

--Note: All atoms are identical; the face-centered atoms are shaded

differently only for ease of viewing.

• Coordination # = 12

Adapted from Fig. 3.1(a),

Callister 6e.

Click on image to animate

(Courtesy P.M. Anderson)

6

body centered cubic structure bcc
BODY CENTERED CUBIC STRUCTURE (BCC)

• Close packed directions are cube diagonals.

--Note: All atoms are identical; the center atom is shaded

differently only for ease of viewing.

• Coordination # = 8

Adapted from Fig. 3.2,

Callister 6e.

Click on image to animate

(Courtesy P.M. Anderson)

8

hexagonal close packed structure hcp
HEXAGONAL CLOSE-PACKED STRUCTURE (HCP)

• ABAB... Stacking Sequence

• 3D Projection

• 2D Projection

Adapted from Fig. 3.3,

Callister 6e.

• Coordination # = 12

• APF = 0.74

10

slide23

Mechanical Testing and Properties

  • Tensile Strength  Tensile Test
  • Flexural Strength  Bend Test for brittle materials
  • Hardness  Hardness Test
  • Toughness  Impact Test
  • Fatigue Life  Fatigue Test
  • Creep rate  Creep Test
slide25

Mechanical Testing and Properties

Tensile Test & the properties obtained from the Tensile Test

  • Note: in Metals, Yield stress is usually the stress required for dislocations to slip.
slide26

Tensile Test & the properties obtained from the Tensile Test

Note: Young’s modulus is a measure of the stiffness of the material.

slide27

Tensile Test & the properties obtained from the Tensile Test

Er=1/2(yield strength)(strain at yielding)

slide28

Tensile Test & the properties obtained from the Tensile Test

Er=1/2(yield strength)(strain at yielding)

slide30

The Bend Test for Brittle Material

  • Due to the presence of flaw at the surface,
  • in many brittle materials, the normal tensile
  • test cannot easily be performed.
slide36

6.7 The Impact Test  impact strength

To evaluate the brittleness of a material subjected to a sudden blow.

slide37

6.7 The Impact Test  impact strength

Impact strength vs. Temperature

Note: BCC metals have transition temperature, but most FCC metals do not.

slide38

6.7 The Impact Test  impact strength

Yield Strength: A > B

Impact Strength: B > A

slide41

The Creep Test:

Apply stress to a material at an elevated temperature

Creep: Plastic deformation

at high temperature

  • a typical creep curve showing the strain produced as
  • a function of time for a constant stress and temperature.