MATERIALS FABRICATION

2012-2013 Term 2

Course Notes

COURSE DESCRIPTION
This course deals with analytical descriptions of the plasticity, metal forming and materials processing operations of both metallic and nonmetallic materials. It is taught to students in Mechanical Engineering, Materials Science and Engineering and Manufacturing Engineering. The first part of the course will describe the analytical basis of plasticity and its application to processes such as rolling, extrusion, wire drawing, forging and sheet metal forming. The second portion of the course will deal with the processing of powders and shaping of ceramics, the processing of polymers, and (it time permits) the casting and joining of materials.

Three lectures: Tuesday, Wednesday and Friday, 9:30 am to 10:20am, ABB-102

Prerequisite: One of ME3A03, Matls3M03, Matls3P03 and Eng3P03

COURSE OBJECTIVES:
The objective of the course is to provide the student with a set of skills which can be applied directly to the forming nd maerials processing industries and which can serve as a basis for graduate research work in forming, materials processing and manufacturing.

At the conclusion of thsi course, the student shoudl have:

1. A quantitative understanding of the elastic, plastic and fracture properties of materials, and their relation to materials processing.
2. Understanding of the constitutive laws used to describe mechanical behaviour of materials and the critical parameters related to forming operations.
3. Understanding of the bulk forming processes of metallic and non-metallic materials and techniques for analysis material behaviour during these processes.

COURSE REFERENCE MATERIAL

PRIMARY TEXTBOOK:
"Metal Forming" (3rd Edition) by Hosford and Cadell

SUPPLEMENTARY TEXTS (ON LIBRARY RESERVE):
Dieter, Mechanical Metallurgy
T.H. Courtney, Mechanical Behaviour of Materials
Cottrell, Mechanical Properties of Matter
A. Kelly and G.W. Groves, Crystallography and Crystal Defect

Students are expected to follow the prescribed textbook: "Metal Forming (second edition) by Hosford and Cadell for the first module. Students are advised to purchase this book from the McMaster Bookstore. A copy of the text will be placed on reserve in the Thode Library. Additional text: “Mechanical Metallurgy” (third edition) by Dieter will also be placed on reserve in the Thode Library. Lecture notes will be placed on the course WebCT. The students are encouraged to read the notes prior to coming to the class as well as bring a copy of the lecture notes to the class.

COURSE OPERATING INFORMATION
The course will be divided between 2 modules. The first module (about 75%-80% of
the course) is based on a textbook titled: Metal Forming by Hosford and Cadell and will
cover Chapters 1-7 and 11-16. These chapters deal with (i) mechanical response and
testing of materials, (ii) multiaxial plasticity, yield surfaces, flow rules and anisotropic
plasticity, (iii) plasticity descriptions of rolling, extrusion, wire drawing, forging and
sheet metal forming. The second module (remaining 20%-25%) will deal with analytical
treatment of ceramic powder processing and shaping, polymer processing, casting and welding (if time permits). No textbook is assigned for this part, handouts will be provided to the students. One demonstration laboratory related to Processing of Polymer Materials will be given to the students on Nov.6th and 7th (see Special Dates/Deadlines).

EVALUATION:

Assignments 25%
2 Mid-Term Tests 30%
Final Exam 45%
McMaster standard calculator allowed.

ASSIGNMENT MODE: Problem assignments discussed in tutorial periods. The assignment
drop off box is located in JHE second floor, MSE wing. A pick up tray will be placed in the MSE JHE-357 Materials Office (with course number marked) to pick up the marked assignment when they become available. Assignment solutions will be posted on the course web site once the marking has been completed.

ASSIGNMENT DUE DATES: Assignment due dates will be indicated on every assignment.
Students will have in average 1.5 - 2 weeks to complete assignment.

DETAILED COURSE OUTLINE

Lecture Topics
1. Stress and strain
Stress at a point, stress tensor, equilibrium equations, stress transformation equations, 2D or plane stress, Mohr’s circle for stress transformation, strain, 2D or plane strain, strain tensor, strain transformation equations, isotropic elasticity, elastic work (strain energy).
2. Macroscopic plasticity and yield criteria
Tresca and Mises yield criteria, plastic work, effective stress, effective strain, flow rules or plastic stress strain relationships, normality principle.
3. Work Hardening
Uniaxial tensile test, mechanical properties, elastic-plastic transition, enginnering and true stress strain curves, power law, necking in a tensile test, direct compression, bulge test, plane strain compression test and torsion.
4. Plastic instability
Instability in uniaxial and biaxial tension, instability of thin walled sphere and tubes, significance of instability, effect of material inhomogeneity on uniform strain.
5. Strain rate and temperature
Stress-strain rate relationship, strain rate sensitivity, superplasticity, effect of strain rate
sensitivity and material inhomogeneity on uniform deformation, combined strain and strain rate effects, temperature dependence of flow stress and temperature rise during deformation.
6. Ideal work (or uniform energy)
Concept of ideal work, applications to extrusion and wire rod drawing, friction, redundant work and mechanical efficiency, maximum drawing reduction.
7. Slab analyis (or force balance)
Plane strain sheet drawing, slab versus ideal work method, wire or rod drawing, direct
compression in plane strain, axisymmetric compression and flat rolling, joints in shear.
8. Formability
Role of microstructure and stress state on formability, bulk formability and forming limits.
9. Bending
Springback in sheet bending, bending with superimposed tension and sheet bandability.
10. Plastic anisotropy
Crystallographic basis of anisotropy, measurement of anisotropy and Hill’s theory of anisotropy.
11. Cupping, redrawing and ironing
Analysis of cup drawing process, effect of work hardening on cup drawability, deformation
efficiency, effect of tooling on drawability, earing, redrawing and ironing of cups.
12. Forming limits
Localized necking in biaxial stretching, forming limit diagrams, experimental and theoretical
forming limit diagram determination.
13. Sheet metal stampings and tests
Strain distribution, drawbeads, wrinkling, cupping tests, limiting dome height test, stretch
flaging, springback of formed components.
14. Polymer processing
Polymer properties and shaping, yielding in polymers, typical stress-strain curves for polymers, elastic properties and yielding, effect of hydrostatic pressure, yield surface representation, analysis of a polymer extruder, effects of nonlinear viscosity, shaping of polymers via a range of polymer processing methods such as extrusion, injection moulding, blow moulding, film blowing, calendaring, compression moulding and transfer moulding.
15. Ceramic processing
Engineering ceramics properties, strength, modulus of rupture, Weibull statistics, use of strength data in design. Powder processing, preconsolidation and shaping of ceramics via uniaxial pressing, isostatic pressing, hot pressing and hot isostatic pressing and various casting methods such as slip casting, drain casting, vacuum casting etc.

POLICY REMINDERS
The Faculty of Engineering is concerned with ensuring an environment that is free of all
adverse discrimination. If there is a problem, that cannot be resolved by discussion among
the persons involved, individual are reminded that they should contact the Department
Chair, the Sexual Harassment Office or the Human Rights Consultant, as soon as possible.

The Senate Resolution on Course Outlines states that:

"students should be reminded that they should read and comply with the "Statement on
Academic Ethics and the Senate Resolution on Academic Dishonesty" as found in the
Senate Policy Statements distributed at registration and available in the Senate Office.

Academic dishonesty consists of misrepresentation by deception or by other fraudulent
means and can result in serious consequences, e.g. the grade of zero on an assignment, loss of credit with a notation on the transcript (notation reads: “Grade of F assigned for
academic dishonesty”), and/or suspension or expulsion from the university.

It is your responsibility to understand what constitutes academic dishonesty. For
information on the various kinds of academic dishonesty please refer to the Academic
Integrity Policy, specifically Appendix 3, located at:
http://www.mcmaster.ca/senate/academic/ac_integrity.htm

The following illustrates only three forms of academic dishonesty:

1. Plagiarism, e.g. the submission of work that is not one’s own or for which other
credit has been obtained.
2. Improper collaboration in group work.
3. Copying or using unauthorized aids in tests and examinations.