Materials Science & Engineering
- ENG MS 306: Introduction to Materials Science
Undergraduate Prerequisites: CAS PY 212; CASPY313 recommended.
Structure and properties of solids; crystalline structure; defect structures; atom movement and diffusion; nucleation and growth; deformation; phase diagrams; strengthening mechanisms; heat treatment; ferrous/nonferrous alloys; ceramics; polymers; composites. Includes lab. Meets with ENGME306. Students may not receive credit for both.
- ENG MS 465: Materials Processing
Undergraduate Prerequisites: ENG EK 156 ; ENG ME 305 ; ENG ME 306; and ENGME304 or ENGEK424
he influence of manufacturing processes on structure and properties of materials. Manufacturing by liquid and solid state processing techniques, material removal processes and bonding and joining processes. Surface modification techniques for enhancing performance and product service life. Includes lab. Meets with ENGME465. Students may not receive credit for both.
- ENG MS 500: Special Topics in Materials Science and Engineering
Undergraduate Prerequisites: Graduate standing or consent of instructor. Specific prerequisites vary according to topic.
Coverage of a specific topic in materials science and engineering. Subject varies from year to year and is generally from an area of current or emerging research.
- ENG MS 503: Kinetic Processes in Materials
Undergraduate Prerequisites: Undergraduate course in materials science and engineering.
Kinetics of mass transport, continuum and atomistic approaches, chemical diffusion; kinetics of chemical reactions, kinetics of adsorption and evaporation; nucleation and growth; solidification; spinodal decomposition; coarsening; martensitic transformations; order-disorder reactions; point defects and their relation to transport kinetics. Meets with ENGME503; students may not receive credit for both.
- ENG MS 504: Polymers and Soft Materials
An introduction to soft matter for students with background in materials science, chemistry, and physics. This course covers general aspects of structures, properties, and applications of soft materials such as polymers, colloids, liquid crystals, amphiphiles, gels, and biomaterials. Emphasis on chemistry and forces related to molecular self-assembly. Topics include forces, energies, kinetics in material synthesis, growth and transformation; methods for preparing synthetic materials; formation, assembly, phase behavior, and molecular ordering of synthetic soft materials; structure, function, and phase transition of natural materials such as nucleic acids, proteins, polysaccharides, and lipids; techniques for characterizing the structure, phase and dynamics of soft materials; application of soft materials in nanotechnology. Meets with ENG ME 504; students may not receive credit for both.
- ENG MS 505: Thermodynamics and Statistical Mechanics
Undergraduate Prerequisites: Undergraduate course in Thermodynamics.
The laws of thermodynamics; general formulation and applications to mechanical, electromagnetic and electromechanical systems; thermodynamics of solutions, phase diagrams; thermodynamics of interfaces, adsorption; defect equilibrium in crystals; statistical thermodynamics, including ensembles, gases, crystal lattices, and phase transitions. Same as ENGME505; students may not receive credit for both.
- ENG MS 507: Process Modeling and Control
Undergraduate Prerequisites: ENG EK 307 and CAS MA 226; or equivalent coursework and permission of the instructor. Senior or graduate standing in engineering.
An introduction to modeling and control as applied to industrial unit processes providing the basis for process development and improvement. Major themes include an integrated treatment of modeling multi-domain physical systems (electrical, mechanical, fluid, thermal), application of classical control techniques, and system design. Topics include modeling techniques, analysis of linear dynamics, control fundamentals in the time and frequency domain, and actuator selection and control structure design. Examples drawn from a variety of manufacturing processes and case studies. Meets with ENGME507. Students may not receive credit for both.
- ENG MS 508: Computational Methods in Materials Science
Undergraduate Prerequisites: ENG MS 503 and ENG MS 505; Or ENGME503 and ENGME505
Introduction to computational materials science. Multi-scale simulation methods; electronic structure, atomistic, micro-structure, continuum, and mathematical analysis methods; rate processes and rare events. Materials defect theory; modeling of crystal defects, solid micro-structures, fluids, polymers, and bio-polymers. Materials scaling theory: phase transition, dimensionality, and localization. Perspectives on predictive materials design. Same as ENGME508; students may not receive credit for both.
- ENG MS 523: Mechanics of Biomaterials
Undergraduate Prerequisites: ENG EK 301 and ENG ME 305.
. Covers the chemical composition, physical structure, and mechanical behavior of engineering materials and the tissues they sometimes replace. Study of materials classes; materials selection; deformation of an elastic solid; yield and fracture; fundamentals of viscoelastic phenomena such as creep, stress relaxation, stress rupture, mechanical damping, impact; effects of chemical composition and structure on mechanical properties; methods of chemical property evaluation. Fracture and fatigue. Influences of plastics fabrication methods on mechanical properties. Emphasis on recent research techniques and results. Discussion of practical matters in medical device design including regulatory approvals, sterilization, packaging and quality control. Students will complete a semester-long design project. Same as ENG ME 523 and ENG MS 523; students can only receive credit for one of these courses. 4 cr.
- ENG MS 524: Skeletal Tissue Mechanics
Undergraduate Prerequisites: ENG EK 301 ; ENG ME 302 ; ENG ME 305 ; ENG ME 309 ; CAS MA 242; or equivalent
The course is structured around classical topics in mechanics of materials and their application to study of the mechanical behavior of skeletal tissues, whole bones, bone-implant systems, and diarthroidal joints. Topics include: mechanical behavior of tissues, (anisotropy, viscoelasticity, fracture and fatigue) with emphasis on the role of the microstructure of these tissues; structural properties of whole bones and implants (composite and asymmetric bean theories); and mechanical function of joints (contact mechanics, lubrication, and wear). Emphasis is placed on using experimental data to test and to develop theoretical models, as well as on using the knowledge gained to address common health related problems related to aging, disease, and injury. Meets with ENGME524 and ENGBE524. Students may not receive credit for both.
- ENG MS 526: Simulation of Physical Processes
Undergraduate Prerequisites: Senior or graduate standing in the engineering, physics, or the chemistry disciplines, or consent of instructor.
Modern simulation methods are covered for describing and analyzing the behavior of realistic nonlinear systems that occur in the engineering and science disciplines. By developing and applying such methods and tools, much deeper understanding, insight, and control of novel technologies can be gained, thereby often greatly aiding technology development, and sometimes providing the leverage to turn a novel technology into a practical reality. Advanced numerical methods are covered for attacking nonlinear partial differential equations. Key aspects of the finite element method. Extensive use is made of the modern computational tools Maple and Scientific Workplace. Examples including problems in micro- and nanoelectronics, bioengineering, material science, photonics, and physics are introduced and related to sensing instrumentation and control. Meets with ENGME526. Students may not receive credit for both. 4 cr. On Demand
- ENG MS 527: Transport Phenomena in Materials Processing
Undergraduate Prerequisites: ENG ME 304; or equivalent or consent of instructor
Introduction to momentum, heat and mass transport phenomena occurring in various processes. Whereas transport phenomena underlie many processes in engineering, agriculture, meteorology, physiology, biology, analytical chemistry, materials science, pharmacy and other areas, they are key to specific applications in diverse areas such as materials processing, green manufacturing of primary materials, biological membranes, fuel cell engineering, synthesis of clean fuels. This course covers three closely related transport phenomena: momentum transfer (fluid flow), energy transfer (heat flow) and mass transfer (diffusion). The mathematical underpinnings of all three transport phenomena are closely related and the differential equations governing them are frequently quite similar. Since in many situations the three transport phenomena occur together, they are presented and studied together in this course. Meets with ENGME27. Students may not receive credit for both.
- ENG MS 530: Introduction to Micro- and Nano-mechanics of Solids
Undergraduate Prerequisites: CAS PY 313 or CAS PY 354 or ENG ME 307 or ENG ME 309; or equivalent or consent of instructor
Mechanics and physics of solids at the nanometer scale: introductory graduate level course for students with background in undergraduate engineering mechanics (or solid state physics) and mathematics. Review of continuum solid mechanics fundamentals. Introduction to dislocation theory. Continuum elastic theory of dislocations. Mechanics of thin films. Review of fundamentals of solid state physics. Electron motion in a periodic potential. Derivative of bulk material properties from free-electron and free-atom models. Phonons. Introduction to atomistic computational methods. Meets with ENGME530. Students may not receive credit for both.
- ENG MS 532: Atomic Structures and Dislocations in Materials
Undergraduate Prerequisites: ENG ME 305 and ENG ME 306; or graduate standing
Relates mechanical behavior of crystalline materials to processes occurring at microscopic and/or atomic levels. Topics covered include structure of materials and their determination by X-ray diffraction; dislocations and their relationship to plastic deformation and strength of materials; fracture and creep. Meets with ENGME532. Students may not receive credit for both.
- ENG MS 534: Materials Technology for Microelectronics
Undergraduate Prerequisites: Graduate status or consent of instructor.
This course deals with the materials issues in microelectronics processing. Fundamental materials science concepts of bonding, electronic structure, crystal structure, defects, diffusion and phase diagrams are applied to key processing steps in microelectronics technology; including single crystal growth, lithography, thermal oxidation of Si, dopant diffusion, ion implantation, thin film deposition, etching and interconnect technology; as well as widely used microelectronics simulation software such as SUPREM. Materials challenges in emerging directions in micro and nanoelectronics, including silicon on insulator technology, Si-Ge strained layers, and quantum dots will also be addressed. 4 cr. summer and either sem.
- ENG MS 535: Green Manufacturing
Undergraduate Prerequisites: Senior/graduate standing; CASCH101 or CASCH131; CASMA226; ENGME304 orENGEK424; ENGME465 or ENGME529; or consent of instructor.
Provides a systems view of the manufacturing process that aims to efficiently use energy, water, and raw materials to minimize air and water pollution and generation of waste per unit of the manufactured product. Specifically, the course will discuss methods to maximize yield and minimize waste effluents in processes, ways to devise treatment strategies for handling manufacturing wastes, innovative ways to decrease energy consumption in manufacturing, by-product use and product recycling, and policies that encourage green manufacturing. Meets with ENGME535. Students may not receive credit for both. 4 cr.
- ENG MS 539: Introduction to Materials Science and Engineering
MS539 is an introductory gradute level course in Materials Science and Engineering. It is intended for students who wish to be introduced to the basics of why materials behave the way they do. It covers topics such as atomic bonding, why and how solids form and their structures, phase transitions, phase diagrams, electronic/magnetic/optical/thermal properties of materials, materials processing and how it influences their properties, ceramics, polymers, ferrous and non-ferrous metals, glasses and societal concern in the use and re-use of materials. This is a 4 credit course.
- ENG MS 545: Electrochemistry of Fuel Cells and Batteries
Undergraduate Prerequisites: ENG ME 529.
Electrochemistry of high temperature fuel cells, batteries and ceramic gas separation membranes. Types, advantages and disadvantages of fuel cells currently being developed by the power generation industry, and the electrochemical underpinnings of fuel cell operation. Thermodynamics of fuel cells, electrode kinetics and mass transport in porous electrodes. Measurements techniques (dc polarization, ac impedance spectroscopy and blocking electrodes) used extensively in fuel cell research and development. Operation of batteries and ceramic gas separation membranes. Current manufacturing techniques used in fuel cell industry. Meets with ENGME545. Students may not receive credit for both.
- ENG MS 549: Structure and Function of the Extracellular Matrix
This is an introductory course dealing with the detailed structure of the basic units of the extracellular matrix including collagen, elastin, microfibrils and proteoglycans as well as the functional properties of these molecules. The focus is mostly on how the structure of these components determine the functional properties such as elasticity at different scales from molecule to fibrils to organ level behavior. The biological role of these components and their interaction with cells is also covered. Interaction ofenzymes and the matrix in the presence of mechanical forces is discussed. Mathematical modeling is applied at various length scales of the extracellular matrix that provides quantitative understanding of the structure and function relationship. Special topics include how diseases affect extracellular matrix in the lung, cartilage and vasculature. The relevance of the properties of native extracellular matrix for tissue engineering is also discussed. Meets with ME 549 and BE 549. 4 cr.
- ENG MS 555: MEMS: Fabrication and Materials
This course will explore the world of microelectromechanical devices and systems (MEMS). This requires an awareness of design, fabrication, and material issues involved in MEMS. The material will be covered through a combination of lectures, case studies, and individual homework assignments. The course will cover design, fabrication technologies, material properties, structural mechanics, basic sensing and actuation principles, packaging, and MEMS markets and applications. The course will emphasize MEMS fabrication and materials. Meets with ENGME555. Students may not receive credit for both.
Diffusion creep refers to the deformation of crystalline solids by the diffusion of vacancies through their crystal lattice. Diffusion creep results in plastic deformation rather than brittle failure of the material.
Diffusion creep is more sensitive to temperature than other deformation mechanisms. It usually takes place at high homologous temperatures (i.e. within about a tenth of its absolute melting temperature). Diffusion creep is caused by the migration of crystalline defects through the lattice of a crystal such that when a crystal is subjected to a greater degree of compression in one direction relative to another, defects migrate to the crystal faces along the direction of compression, causing a net mass transfer that shortens the crystal in the direction of maximum compression. The migration of defects is in part due to vacancies, whose migration is equal to a net mass transport in the opposite direction.
Crystalline materials are never perfect on a microscale. Some sites of atoms in the crystal lattice can be occupied by point defects, such as "alien" particles or vacancies. Vacancies can actually be thought of as chemical species themselves (or part of a compound species/component) that may then be treated using heterogeneous phase equilibria. The number of vacancies may also be influenced by the number of chemical impurities in the crystal lattice, if such impurities require the formation of vacancies to exist in the lattice.
A vacancy can move through the crystal structure when the neighbouring particle "jumps" in the vacancy, so that the vacancy moves in effect one site in the crystal lattice. Chemical bonds need to be broken and new bonds have to be formed during the process, therefore a certain activation energy is needed. Moving a vacancy through a crystal becomes therefore easier when the temperature is higher.
The most stable state will be when all vacancies are evenly spread through the crystal. This principle follows from Fick's law:
In which Jx stands for the flux ("flow") of vacancies in direction x; Dx is a constant for the material in that direction and is the difference in concentration of vacancies in that direction. The law is valid for all principal directions in (x, y, z)-space, so the x in the formula can be exchanged for y or z. The result will be that they will become evenly distributed over the crystal, which will result in the highest mixing entropy.
When a mechanical stress is applied to the crystal, new vacancies will be created at the sides perpendicular to the direction of the lowest principal stress. The vacancies will start moving in the direction of crystal planes perpendicular to the maximal stress. Current theory holds that the elasticstrain in the neighborhood of a defect is smaller toward the axis of greatest differential compression, creating a defect chemical potential gradient (depending upon lattice strain) within the crystal that leads to net accumulation of defects at the faces of maximum compression by diffusion. A flow of vacancies is the same as a flow of particles in the opposite direction. This means a crystalline material can deform under a differential stress, by the flow of vacancies.
Highly mobile chemical components substituting for other species in the lattice can also cause a net differential mass transfer (i.e. segregation) of chemical species inside the crystal itself, often promoting shortening of the rheologically more difficult substance and enhancing deformation.
Types of diffusion creep
Diffusion of vacancies through a crystal can happen in a number of ways. When vacancies move through the crystal (in the material sciences often called a "grain"), this is called Herring-Nabarro Creep. Another way in which vacancies can move is along the grain boundaries, a mechanism called Coble creep.
When a crystal deforms by diffusion creep to accommodate space problems from simultaneous grain boundary sliding (the movement of whole grains along grain boundaries) this is called granular or superplastic flow. Diffusion creep can also be simultaneous with pressure solution. Pressure solution is, like Coble creep, a mechanism in which material moves along grain boundaries. While in Coble creep the particles move by "dry" diffusion, in pressure solution they move in solution.
Each plastic deformation of a material can be described by a formula in which the strain rate () depends on the differential stress (σ or σD), the grain size (d) and an activation value in the form of an Arrhenius equation:
In which A is the constant of diffusion, Q the activation energy of the mechanism, R the gas constant and T the absolute temperature (in kelvins). The exponents n and m are values for the sensitivity of the flow to stress and grain size respectively. The values of A, Q, n and m are different for each deformation mechanism. For diffusion creep, the value of n is usually around 1. The value for m can vary between 2 (Nabarro-Herring creep) and 3 (Coble creep). That means Coble creep is more sensitive to grain size of a material: materials with larger grains can deform less easily by Coble creep than materials with small grains.
Traces of diffusion creep
It is difficult to find clear microscale evidence for diffusion creep in a crystalline material, since few structures have been identified as definite proof. A material that was deformed by diffusion creep can have flattened grains (grains with a so called shape-preferred orientation or SPO). Equidimensional grains with no lattice-preferred orientation (or LPO) can be an indication for superplastic flow. In materials that were deformed under very high temperatures, lobate grain boundaries may be taken as evidence for diffusion creep.
Diffusion creep is a mechanism by which the volume of the crystals can increase. Larger grain sizes can be a sign that diffusion creep was more effective in a crystalline material.
- ^Passchier & Trouw 1998; p. 257
- ^Twiss & Moores 2000, p. 391
- ^Twiss & Moores 2000; p. 390-391
- ^Twiss & Moores 2000, p. 394
- ^Passchier & Trouw 1998; p. 54
- ^Passchier & Trouw 1998; p. 42
- ^Gower & Simpson 1992
- Gower, R.J.W. & Simpson, C.; 1992: Phase boundary mobility in naturally deformed, high-grade quartzofeldspatic rocks: evidence for diffusion creep, Journal of Structural Geology 14, p. 301-314.
- Passchier, C.W. & Trouw, R.A.J., 1998: Microtectonics, Springer, ISBN 3-540-58713-6
- Twiss, R.J. & Moores, E.M., 2000 (6th edition): Structural Geology, W.H. Freeman & co, ISBN 0-7167-2252-6