Portland Community College | Portland, Oregon

Introduces the study of Materials Science and Engineering where the macro or bulk properties of materials are related to its microstructure. Once this relationship is understood, modifications to a material can be "engineered" to provide the desired property enhancement.
In depth study of mechanical properties of metals are emphasized. Survey of mechanical properties of ceramics and polymers included. A basic understanding of general chemistry is helpful in understanding materials characterization on the basis of the type and strength of the primary interatomic bonding prevalent in the selected material.
Mathematics involves applied algebra and trigonometry, for example in solving exponential and logarithmic equations and in area, volume and density calculations. Knowledge of differential and integral calculus is helpful in order to understand the derivation of the governing equations and formulas used to describe material characteristics.
On another level of characterization, students will sketch three-dimensional cubic and hexagonal crystal structures found predominantly in metals.
In Lab, the emphases are safety, teamwork, data measurement/analysis, and lab documentation using computer applications. Hands-on labs develop tactile ability for preparation of metallographic samples for microscopic examination and photographic documentation of the microstructures of samples subjected to a variety of thermal processing that affect mechanical properties for steel and aluminum alloys. A team project with oral report is required prior to lab completion.

The student will be able to:

1. Describe the fundamental structure and related properties of individual materials, classified as metals, ceramics or polymers by free hand sketching and by calculation of specific physical and chemical properties.
2. Utilize textbook data from tables, charts, and graphs for gathering data needed for problem solution in homework and exams.
3. Relate textbook and lecture information to lab activities.
4. Follow directions and ask for needed help in order to achieve successful results in the lab.
5. Work safely in small teams during lab activities.
6. Present an oral report of a portion of their lab team project.
7. Use computer applications (including grammar/spell checks) for consistent and well-documented lab write-ups.

Individual, small group, and full class discussion; homework problems; laboratory proficiency; exams; team project participation will be used to assess stated outcomes. Lecture, homework, and laboratory will be coordinated. A hands-on lab with written reports will be required and shall support several key concepts presented in lecture. Lab work will be conducted in teams of 3 to 4 students.
Specific evaluation procedures will be provided at initial class meeting.
Grades will be determined on the basis of homework, examinations, and laboratory participation and quality of the individual written lab report. An oral presentation covering a team research project of a materials science topic area will be required. Student progress in lecture will be measured by performance on objective examinations covering appropriate types of problems.

THEMES, CONCEPTS, AND ISSUES:

1. Material properties are directly influenced by their microstructures.
2. Understanding structure-property relationships allow modification or engineering of materials to perform well in a specific application.
3. Metals are microstructurally the simplest to characterize.
4. A thorough knowledge of the structure-property relationships of metals can be beneficial in the study of ceramics and polymers.
5. Due to time constraints and lab capabilities only certain properties, primarily mechanical, of certain common metals can be studied in depth.

CONTENT:

1. Fundamental Concepts
   1. Structure and energy of atoms
   2. The periodic table
   3. Atomic bonding and coordination
   4. Classification of materials
   5. Quantum theory
   6. Electronic Properties
   7. Energy band theory
   8. Conductors and insulators
   9. Semiconductors
2. Crystals and Microstructure
   1. Phases and microstructure
   2. Single crystals
   3. Crystal geometry
   4. Polycrystalline phases
   5. Metallic structures
   6. Ceramic structures
   7. Polymeric structures
3. Mechanical Properties
   1. Stress and strain
   2. Engineering stress and strain
   3. True stress and strain
   4. The tension test
   5. Elastic behavior
   6. Plastic deformation
4. Defects in crystalline solids
   1. Point defects
   2. Dislocations
   3. Critical stresses for slip and fracture in single crystals
5. Equilibrium Relationships In Materials
   1. Equilibrium diagrams and phase analysis
   2. Solid solutions in multi-component systems
   3. Invariant reactions in binary systems
6. Rate Processes
   1. Arrhenius Equation
   2. Solid state diffusion theory
   3. Steady state diffusion
   4. Non steady state diffusion
   5. Transformations by nucleation and grain growth
7. Processing Of Metals
   1. Cold work - anneal cycles
   2. Recovery, recrystallization, and grain growth
   3. Solid state reactions and heat treatment
   4. Precipitation hardening treatment
   5. Eutectoid decomposition treatment
8. Steel Heat Treatment
   1. The iron-iron carbide phase diagram
   2. The pearlitic transformation
   3. The martensitic transformation
   4. Isothermal transformation curves
   5. Continuous cooling transformation curves
   6. Steel heat treatments:
      1. Quenching
      2. Tempering
      3. Annealing
      4. Normalizing
   7. Hardness and hardenability
   8. Classification of steels
   9. Surface and local hardening methods:
      1. Carburizing
      2. Nitriding
9. Non-metal Engineering Materials
   1. Ceramics:
      1. Crystalline ceramics
      2. Amorphous ceramics (glasses)
      3. Carbon and carbides
      4. Applications
   2. Polymers:
      1. Polymerization reactions
      2. Types of polymers
      3. Fabrication methods
      4. Applications
10. In the laboratory
    1. Understand the importance of safety and follow all safety procedures
    2. Watch chemical safety video and sign off sheet
    3. Å·ÖÞ±­¾öÈü¾º²Âapp_Å·ÖÞ±­×ãÇòÍø-Ͷע|¹ÙÍø skills necessary for metallographic (microscopic) examination of metallic sample surfaces:
       1. Chamfer and power grind (eye protection required)
       2. Manual sanding on graded wet bench
       3. Polish on graded abrasive wet slurry stations
       4. Chemically etch polished surface (eye and skin protection required)
       5. Photograph etched samples with the digital camera attached to the microscope
    4. Perform consistent Rockwell and Brinell (indentation) hardness tests
       1. Semi-automated indentation hardness testers
       2. Manual indentation hardness testing
    5. Perform tensile testing on the Tinius-Olson testing machine
       1. Inspect and select tensile test specimen
       2. Measure and mark gage length and gage diameter
       3. Fit and install specimen to the testing machine
       4. Install and calibrate the extensometer
       5. Install and calibrate the graph paper; place pen tip on paper
       6. Select the speed and conduct the test through the elastic region
       7. Stop test and remove the extensometer
       8. Resume test until failure of the specimen
       9. Stop test and remove failed specimen and plotted graph
       10. Measure the gage length and gage diameter of the failed specimen
       11. Record yield load and ultimate tensile load on the graph
       12. Calculate yield strength, ultimate tensile strength, percent elongation, percent area reduction, and Young's modulus (modulus of elasticity)
    6. Perform quench and temper heat treatment on selected plain carbon and/or low alloy steels
       1. Perform hardness testing to compare the effects of quench media (air, oil, or water)
       2. Perform hardness testing to compare the effects of tempering time (holding temperature constant)
       3. Photograph etched steel samples with the digital camera attached to the microscope
    7. Perform solution heat treatment and precipitation/age heat treatments on selected aluminum alloys
       1. Perform hardness testing and/or tensile tests on selected samples
       2. Correlate Brinell hardness tests with tensile tests
       3. Photograph etched aluminum samples with the digital camera attached to the microscope

COMPETENCIES AND SKILLS:
The student will be able to:

1. Describe the structure-property relationship underlying the Materials Science and Engineering (MSE) field of study.
2. Perform a variety of calculations that pertain to properties of materials, primarily mechanical, primarily to metals and their alloys. (For example:)
   1. Coordination number (CN).
   2. Packing factor (PF).
   3. Density (mass, linear, planar).
   4. Steady-state diffusion flux.
   5. Diffusivity, or diffusion coefficient.
   6. Percent coldwork.
   7. (And others).
3. Sketch easy to visualize isometric or oblique pictorials of unit cells of common cubic and non-cubic metal crystal structures including:
   1. Body-centered cubic (BCC).
   2. Face-centered cubic (FCC).
   3. Simple cubic (SC).
   4. Tetragonal variants (body-centered tetragonal, BCT; face-centered tetragonal, FCT).
   5. Hexagonal close-packed (HCP).
   6. Crystallographic direction and planar (Miller) indices.
4. With respect to Equilibrium Phase Diagrams (Binary systems)
   1. Look up the correct phase diagram for the given system.
   2. Identify phases present at a given state point.
   3. Report the phase composition for each phase present.
   4. Calculate the mass or weight fractions for each of the phases present using the (inverse) lever rule.
   5. Draw the two sets of levers and calculate the mass or weight fractions of the four main phase microconstituents present with various compositions of the iron-iron carbide equilibrium system.
5. Kinetics of Solid State Binary Systems
   1. Identify the information found in the fraction transformed versus time kinetics graph ("S" curves).
   2. Calculate the rate of the solid state reaction.
   3. Identify the information found on isothermal transformation diagram ("C" curves) for the iron-iron carbide system.
   4. Plot a variety of isothermal heat treatments on the above diagram.
   5. Be aware of the differences between continuous cooling transformations and isothermal. transformations, noting which one is appropriate to use.
6. Perform the required Laboratory activities detailed in the Lab Content above, meeting or exceeding the minimum requirements for process and quality (to be established early in the course).