To consider deformation and strength of metals and alloys, understanding stresses and strains as tensors is needed. The first half of this course teaches the fundamentals of stresses and strains and the relationship between stresses and strains during elastic deformation known as Hooke's law. On the other hand, the second half teaches the plastic deformation of metals and alloys from both microscopic and macroscopic points of view, and explains various strengthening methods on the basis of plastic deformation of crystals and roles of dislocations.
By completing this course, students will be able to:
1) Understand the fundamentals of stresses and strains that are second-rank tensors.
2) Understand the plastic deformation of engineering materials, the atomistic mechanisms of plastic deformation and the roles of dislocations.
stress, strain, tensor, transformation of coordinate systems, distortion, elastic deformation, plastic deformation, Hooke's law, Young's modulus, Poisson's ratio, bulk modulus, shear modulus, elastic coefficients, dislocation, slip deformation, Schmid's law, critical resolved shear stress, yield stress, proof stress, tensile strength, fracture strain, work hardening, strengthening mechanisms, solid-solution strengthening, precipitate strengthening, dispersion strengthening, grain boundary, Hall-Petch relationship.
|✔ Specialist skills||Intercultural skills||Communication skills||Critical thinking skills||✔ Practical and/or problem-solving skills|
Exercise problems are assigned during the course. To prepare for class, students should read the course schedule section and check what topics will be covered. Required learning should be completed outside of the classroom for preparation and review purposes.
|Course schedule||Required learning|
|Class 1||The concept of stress and strain, and deformation of metals and alloys||Deformation and fracture of metals and alloys. Characteristic variables of stress-strain curve such as Young's modulus, yield stress ans tensile strength|
|Class 2||Most simplified expression of stress and strain||Tensile deformation of cylindrical specimen. Load-elongation curve and stress-strain curve|
|Class 3||Definition of traction (vector) and stress (tensor)||Understanding of traction and stress|
|Class 4||Relationships satisfied for stress components||Symmetry of stress components. Relationship between traction and stress. Summation convention of indexed variables|
|Class 5||Coordinate transformations of stress components||Coordinate transformations of vector components. Coordinate transformations of tensor components|
|Class 6||Definition of distortion and strain||Understanding of the concept of distortion and strain|
|Class 7||Elastic coefficients and Hooke's law||Elastic coefficients as forth-rank tensors. Elastic deformation of elastically isotropic materials|
|Class 8||Exercise problems for the first half of this course||Students will be assessed on their understanding of stress and strain, and their ability to apply them to solve problems|
|Class 9||Plastic deformation (yielding phenomena)||Understanding of yielding and motion of dislocations|
|Class 10||Ideal strength and crystal defects||Differences in strength of crystals with and without dislocations|
|Class 11||Crystal plasticity and glide motion of dislocation||Understanding of slip motion of dislocations|
|Class 12||Plastic deformation of single crystal (geometry of slip deformation)||Understanding of Shmid's law and critical resolved shear stress|
|Class 13||Plastic deformation of polycrystal (role of grain boundary)||Understanding of Hall-Petch relationship|
|Class 14||Deformation mechanisms and strengthening methods||work hardening,solid-solution strengthening, precipitate strengthening, dispersion strengthening|
|Class 15||Exercise problems for the second half of this course||Students will be assessed on their understanding of plastic deformation, crystal defects and strengthening methods of metals and alloys, and their ability to apply them to solve problems|
W. D. Callister, Jr: Materials Science and Engineering An Introduction, John Wiley and Sons, Inc.
S. Kohda: Plasticity of metals, Maruzen.
A. Kelly and G. W. Groves: Crystallography and Crystal Defects, Longman Group Ltd., London
Students' knowledge of stress and strain, deformation of single crystal and polycrystal, and their ability to apply them to problems will be assessed. Midterm and final exams 80%, exercise problems 20%.