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The Structure and Characterization of Engineering Materials
Laboratory
 Winter quarter, 2 units
Laboratory - one discussion session and one 3-hour laboratory
session per week
Prerequisite: EMS-162 (may be taken concurrently)Experimental
investigations of the structure of solids are combined with techniques for
testing and evaluation. Laboratory exercises emphasize methods used to
study structure of solids at the atomic and microstructural levels.
Methods focus on optical, x-ray, electron, and ultrasonic techniques.
Contents
- Introduction
- Laboratory Safety
- Laboratory Reports
- Engineering Budgets
- Microstructure of Materials
- X-ray Diffraction
- Other Topics
- Appendices
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Introduction
This course offers demonstrations of and experience with methods of determining the
crystal structure and characterizing the microstructure of engineering
materials. Approximately half of the course focuses on microstructural
characterization using optical microscopy. Students will learn about the
optical microscope, digital imaging and quantitative metallography and will
use this knowledge to fully characterize the microstructure of a prepared
specimen. The second part of this course is devoted to the analysis of
the structure of materials using x-ray diffraction. Students will have the
opportunity to operate a modern diffractometer and will use it to perform
several types of analyses. The third part of the course offers hands-on
demonstrations of non-destructive testing, x-ray radiography, molecular
simulations and electron microscopy.This course consists of 5 experiments, four on x-ray diffraction and a
four-part experiment on the optical microscopy and microstructure of
materials. Download the syllabus to learn more about the specific
experiments we'll do this quarter, the calendar, and other information.
 | Syllabus - the syllabus, including
a listing of experiments we will do and the calendar |
Spreadsheets: A recent addition to this course
has been the incorporation of spreadsheets into many aspects of the
experiments, including preparing for and conducting the experiments,
analyzing the data and preparing figures and tables for the reports.
Several of the homework assignments below include spreadsheet-based
exercises designed to help the students get the most out of the experiments.
If you have never
used spreadsheets such as Corel Quattro Pro or Microsoft Excel before,
consider trying the following exercise from the SAMS (Spreadsheet
Applications for Materials Science) web site:
The exercise covers basic calculations, graphing data, and analyzing
the data, and provides detailed, step-by-step instructions for the
beginner. Top
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2. Laboratory Safety
Safety is an integral part of all
materials science laboratory courses. At the beginning of the quarter
the students are given a tour of the laboratories and shown the potential
hazards, safety features and resources in the laboratories, and a review the
emergency and evacuation procedures. Please visit the
laboratory safety page of this web site for additional information on this important
subject and to view documents that cover specific safety policies and procedures.
Hazards associated with these experiments are summarized in the
Hazards Review document.
Please download it and read it. These issues will be reviewed that
the start of each experiment.
The safety component of this course includes an additional
discussion of x-ray safety. Students are introduced to the terms,
definitions, and policies related to radiation safety and to the safety features
of the x-ray diffractometer. The link below will take you to our x-ray
safety class handout.
Make sure you download, read, and sign the attached form and bring it
with you to the first diffraction experiment. Note - if you don't
bring this form with you you won't be allowed to do the experiment.
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3. Laboratory Reports
Like all of the materials science laboratory
courses at U. C. Davis writing a report after concluding each experiment is
a big part of the course. In this course, where the experiments
deal with fairly complex subjects, students have tendency to write long,
detailed reports that review the principles and techniques employed as well
as the experiment. We'll focus our energies on writing about only the
immediate question that we want to answer using the results from this
experiment.
To help with this we have written a number of documents offering
guidelines, checklists, and suggestions that will help you write your
reports. Please visit the
laboratory reports page to see these documents.
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4. Engineering Budgets
Knowing the costs of doing the experiments done in this course helps
immensely in understanding to cost of doing engineering work and research
and in placing a value on your own time and talents. It also helps in
planning or designing an experiment since it forces you to think it
through, list the supplies and other resources needed, and of course
estimate how much time it will take to complete the experiment or project.
In this exercise we will create budgets for each experiment. A
budget will be created for each experiment and will include the cost of
instrumentation, personnel, and other costs. After doing each
experiment, the actual time and materials will be entered to produce a
costs report. At the end of the quarter one last report will be
written. It provides brief descriptions of the goals and outcomes of
each experiment along with the costs of each experiment and the total
costs of doing all the work in this course.
The following document covers this exercise in more detail. It
also provides a model for developing your budgets and lists the costs of
using the analytical instrument available to us during the term.
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5. Microstructure of Materials
This four-part experiment provides an introduction to the use of the reflected-light microscope,
including digital imaging, image enhancement and analysis and the study of the
microstructures of materials. Each student selects a material to study and performs a full
qualitative and quantitative analysis of its microstructure. The four parts of this experiment are:
- Introduction to the Optical Microscope
Understanding the basics of light optics, lenses, illumination systems and contrast methods are essential if one is to get the most
out of their microscope. The students will study the microscope and determine its basic operating and performance characteristics.
Homework - get familiar with the optical
microscope by answering basic questions about how it works and how the
objective lens's numerical aperture effects the performance of the
microscope. Some of these questions can be answered only after you
have spent a little time using the optical microscopes in our
laboratories.
- Literature Review
Students go to the library to learn as much as they can about the
type of material they will be studying. They must learn the basic terminology for
the classes of alloys, the phases present, and the basic types of structures and
morphologies.
- Qualitative Microstructural Analysis
A qualitative examination of the microstructure
will lead to a clear identification of every phase and feature present in the specimen.
Homework - get better acquainted
with digital imaging as it applies to optical microscopy and learn to
optimize your photo settings for any application.
- Quantitative Microstructural Analysis
All major features of the microstructure are
measured using standard stereological techniques. The emphasis is on using the
correct method correctly, minimizing personal bias, and reporting the results in the
correct manner.
Homework - get more familiar
with the concept of grain size, including ASTM grain size, and measure
grain size and volume fraction of phases from three artificial (idealized)
microstructures.
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Two of the four optical microscopy stations available to students in this course.
Optical micrograph (2x2 montage) of 1095 steel showing the
characteristic pearlite structure with proeutectic cementite at the grain
boundaries.
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6. X-ray Diffraction
This part of the course consist of up to four experiments that teach the
students how x-ray diffraction can be used to analyzes a number of
crystallographic and microstructural characteristics of natural and
engineering materials. The experiments we have used in this course
are:
- Introduction to X-Ray Diffraction
This
experiment provides an introduction to the use of an x-ray diffractometer in investigating
the structure of materials. Students learn how to operate the diffractometer, how to
design, set up and execute an experiment and how to process and interpret
the results.
Homework - A few basic questions on
the basics of x-ray diffraction plus to exercises that ask you to
calculate sections of the diffraction pattern that will be collected
during the experiment.
Procedure - Notes and the complete procedure for this experiment.
- Qualitative and Quantitative Phase Analysis
Using the x-ray diffractometer the students determine the types and
quantity of pure powders in a mixture. The powders are identified by comparing the results
to the standard database of powder diffraction files. The quantities of powders present
are determined by comparing the results to those from a set of standards which the
students generate.
Homework - an exploration of the mass adsorption coefficient and its
effect on diffraction intensity
Procedure - Notes and the complete procedure for this experiment
- Crystallite Size Analysis - 1
The Scherrer and Warren-Averbach methods are used to determine the crystallite size
of nanocrystalline powders
such as 32 nm TiO2 and 24 nm Al2O3. The results
are compared to the manufacturer’s specifications
(SSA method) and to images obtained from electron microscopes.
This experiment is adapted from a paper by Krill et al.
Homework - explore the
concept of crystallite size and size distributions, including a partial
analysis of data from past experiments
Procedure - Notes and the complete procedure for this experiment.
- Crystallite Size Analysis - 2
Samples of nanocrystalline materials from Nanophase and Technanogy
are analyzed in this experiment. The Scherrer equation is the
basis of this experiment. A LaB6 standard is used to
determine the machine's peak broadening characteristics. Many
peaks from the sample's pattern are used in the analysis to work out the
strain component and eventually the crystallite size. This
experiment is adapted from Suryanarayana and Norton's book.
Homework - explore the concept of crystallite size and microstrain and
their measurement, including a run-through of the analysis of the type
of data to be collected during the experiment.
Data - data for the homework
assignment.
Procedure - Notes and the complete procedure for this experiment.
- Residual Stress Measurements
The x-ray diffractometer is used to determine how much the deformation of a piece of steel
has distorted the crystalline lattice. This information is used to estimate the residual
stress in the specimen.
Homework - explore the
concept of residual stress and perform calculations that will help you
understand the results from the experiment
Procedure - Notes and the complete procedure for this experiment
- Measuring Changes in Lattice Parameters and Density Due to Alloying
The x-ray diffractometer is used to make careful measurements of the
lattice parameters of Cu-Zn alloys in order to determine the zinc
content. The procedure involves performing calculations, per
Vegard's law, to predict the change in lattice parameters with zinc
content, followed by a scan of a copper/brass sample where the copper is
used as an internal standard.
Homework - Exercises and calculations related to Vegard's law and careful measurements of d-spacing
Procedure - the complete procedure for this experiment
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The Scintag x-ray diffractometer used in this course.
The five-fingers region of the diffraction pattern for
quartz, calculated in one of the homework exercises.
Nanocrystalline aluminum oxide similar to that analyzed in
the crystallite size experiments.
Profile fitting is used to accurately determine the
intensity and width of the peak. This technique can also work on
partially overlapping peaks like those shown in this segment of the
diffraction pattern of a TiO2 powder.
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7. Other Topics
In addition to the above two parts of the course, one week is set aside
for demonstrations of the following materials characterization
techniques:
- Ultrasonic Inspection
This is a demonstration of ultrasonic inspection techniques
which utilizes a portable inspection unit to perform an inspection on a steel block.
It also includes computer display of ultrasonic inspection data of a flaw in a
composite structure.
- X-Ray Radiography
This is simply a demonstration of x-ray radiographic techniques used
in flaw detection. It includes locating and measuring the sizes of holes drilled in the
back of a plate of steel, locating cracks in a part and identifying items trapped in a
section of tubing. Student’s radiograph their own "specimens".
- Electron Microscopy
The students get a tour of electron microscopes, transmission electron
microscopes along with an introduction to analytical techniques such as EDS
and EBSD.
- Acoustic Microscopy
Demonstrations of imaging and scan modes used to image defects in
microelectronic components and circuit boards.
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An x-ray radiograph of a hard disk drive.
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8. Appendices
The appendices
page on this web site offers a number of documents that you will find useful during and after the laboratory
session. These include operating
procedures for the equipment, tips and trick for digital imaging, and documents that will help you get the
most out out your spreadsheet-based assignments and writing the laboratory
reports. The documents you should look are:
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