1 mime 1650 materials science & engineering spring 2

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MIME 1650 MATERIALS SCIENCE & ENGINEERING
Spring 2020
Introduction to
Materials Science & Engineering – Laboratory
The laboratory portion of MIME 1650 Materials Science &
Engineering seeks to give the
engineering student a hands-on appreciation of what Material
Science is all about. In this
portion of the course the student should gain an understanding
of material properties and these
properties are affected by different processes. The knowledge
of these effects is valuable when
selecting a material for a part or design. For example, certain
applications require a material
that will not buckle under stress; others require more strength
while others require more
ductility. In addition to selecting the right material, engineers
must make their design cost
effective.
There will be seven (7) laboratory exercises spread over the
course of the semester. Each
student will be required to submit a lab report which will be due

one week after the completion
of the lab unless otherwise specified. ALL reports must be
typed. Failure to do so will result
in a rejected report. Details on what is expected from your
report are in the Report
Requirements section. If there are any questions about a
particular lab, please talk to your
Teaching Assistant (TA) about your concerns and they will
provide the needed help. They can
often critique your report upon request. Do not hesitate in
asking questions if something is
confusing to you as asking questions is an excellent way to
learn.
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Laboratory Report Requirements
Introduction
All engineers and scientists are required to write reports
documenting their work. Each
organization establishes its own required format. Reports are
used for a variety of purposes.
First and foremost, it is a historical document of what, when,
why and how something was
done. A reader of the report should, by the report alone, be able
to replicate the experiment. A
report is often used by management to determine whether or not
a project is meeting
expectations. Decisions of where to allocate available resources

(such as labor and capitol) are
often made based on the written report. Engineers and
scientists that communicate well
through the written report are in demand by industry.
Report Style
The report must be clear, concise and complete. A well written
report avoids engineering
jargon and specialized language. The writer must remember
that the reader often does not have
the knowledge or background that the writer has. Ideas must be
expressed in a logical flow and
in complete sentences. Furthermore, the report must be concise.
What this means is that the
writer should favor simple sentences where possible. Long,
flowery sentences with many
subordinate clauses and qualifications are not appropriate in an
engineering report. On many
organizations, the pertinent ideas being reported on must be
stated in one page, often called
“The Executive Summary.” Regardless of what the organization
may require, shorter but
complete reports are desired over long reports. A complete
report indicates the writer is
honestly reporting what happened and why. If a project or
experiment failed, the writer should
clearly state this and then explain why. The report should be
decisive.
The report is a historical document of what occurred.
Therefore, the report should be written in
third person as well as in past tense. Proper English is required
throughout the report. Slang
words are not understood from generation to generation and
may be misinterpreted when a
report is read a decade or so after the writing of the report.

Since the report is archival, the
report must be prepared using word processing software. Hand
written reports are not
acceptable. Not only is this unprofessional, but it reflects
poorly upon the writer.
Report Formatting and Presentation
The following formatting guidelines must be followed
• Report must be printed on 8 ½ inch x 11 inch (letter size)
white paper.
• All pages of the report including raw data, appendices and
sample calculations should
be numbered with the page number centered or right aligned in
the bottom margin
(footer).
• Font size should not be smaller than 10 point Times New
Roman.
• All sections headings should be in bold font.
• Report should use double or 1.5 line spacing.
• Reports must be stapled in the upper left corner before
submission. Stapling of the
report is the author’s responsibility as a stapler will not be
provided.
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Report Structure
The following report structure is required for all laboratory
reports submitted by students in
MIME 1650: Materials Science and Engineering – Laboratory.
Lab reports will be graded out
of 100, with each section weighted as shown.
Title Page 5 points
Objective 5 points
Abstract 5 points
Introduction 10 points
Methodology 10 points
Procedure 10 points
Data 10 points
Results 15 points
Discussion and Conclusion 15 points
References 5 points
Appendices 10 points
Title Page
The title page will consist of the report title, the names of the
author(s) of the report, the
laboratory section and the date of the experiment. This will be
a single page cover sheet.
Objective
The objective of the Report should be stated in ONE sentence.
Several examples are provided
below.
“The objective of this report is to describe the automations of
the 280-OBI Stamping line at
Shiloh Industries.”
“The objective of this report is to report the measurements of

the sample block taken during
Laboratory Exercise One.”
“The objective of this report is to investigate the heat treating
of AISI 4340 steel.”
Abstract
The abstract should describe the entire report including
significant results. The abstract should
not exceed 250 words in length. The Abstract should indicate
to the reader what was
attempted, what was accomplished and what the results were.
Introduction
The report introduction should be one or two paragraphs which
describe the background
material for the report and place the report in context (e.g. why
this test is important and what
the results of this type of test are used for). It should be
interesting to read and should
encourage the reader to read the remainder of the report. The
material contained in the
introduction should be general in nature. The remainder of the
report will provide specifics
where needed. The main purpose of the introduction is to
prepare the reader for what follows
in the report.
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Methodology
This section provides the reader with a general understanding of
the type of experiment which

was performed and how it was conducted. The background
theory for the experiment should
be succinctly discussed. If an analysis method will be used to
process the data, it should be
described here. This section mostly discusses what method was
used for the experiment and
the reason why that method is preferred. The length of this
section will vary depending on the
experiment.
Procedure
This section describes exactly how the experiments were
performed. If necessary, a sketch of
the test setup should be provided. Exact equipment (with serial
numbers for the specific
equipment) used will be described. The order of tasks shall be
presented so that any other
experimenter should be able to follow the procedure. Long,
detailed procedures should be
placed in the Appendix and referenced here.
Data
This section will present the raw data values obtained using the
procedure of the previous
section. Where the data is lengthy, the raw data is placed in an
appendix and referenced here.
Actual data recording forms should be placed in the appendix.
This section should begin with
text describing the data and referring to tables and graphs that
contain the actual data values
when necessary. This section will consist of only values
actually measured. No computations
are allowed on the data values. Computations made on data are
presented in the next section.
Results

Results include observations based on the methodology, the
procedure and the data. It may
consist of computations and presentation of the results in a
tabular or graphical form. When the
computations involve a long string of computations, the sample
computations should be placed
in an appendix and referenced in this section.
Graphs and Tables
The preparation of graphs, figures and tables require that they
be clearly labeled and
professionally presented. In some cases, this may require that
they be presented on a complete
page in landscape orientation (i.e. sideways to the normal
vertical (portrait) direction). If this is
the case, they should be rotated such that the upper right hand
corner of the graph, figure or
table corresponds to the upper left hand corner of the report.
The top of the graph, figure or
table will be at the normal left hand margin of the report.
Graphs should be plotted using computer software such as
Excel, Matlab, Mathcad, etc. Each
axis should be labeled with its variable, symbol and appropriate
units. An appropriate scale
and gridlines should be used. The graph should be labeled with
a suitable title. A legend
should describe the symbols, line styles on the graph, and units.
Gridlines should be numbered
according to the scale used.
Tables should be treated similarly. Tables should be inserted in
the text immediately after they
are referenced. Long tables should be placed in an Appendix.
Tables should be numbered and

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titled. Each column will be labeled with a short heading,
including the units. Where tables run
over several pages, the table will have headings on each page.
Columns of numbers should be
aligned by the decimal point. Columns should be boxed since
free form tables are not allowed
in the report.
Discussion and Conclusion
In this section, the writer reports on the conclusions drawn from
the experimental work.
Conclusions are the important finding determined from the
experiment. All statements must be
supported by the data and the results. Actual values should be
stated or referenced for support.
New information not reported on earlier can not be introduced
in this section. Any judgments
made should pertain directly to the work. For example, a
judgment: “The experiment
corresponded well to the theory since the data differed at most
by 3% from the prediction” is a
valid statement to make in this section since it is directly
supported by the work. However,
“The experiment corresponded well to the theory because the
tools used were new” is not valid.
In many cases, the writer may feel that additional work needs to
be performed on the subject
matter of the report. This may be included in a few short
statements at the end of this section.
References

Any resource used as reference for the work should be
documented here using standard
referencing techniques.
Appendices
This section should be separated from the main report by a
single page with the word
“APPENDICES” centered on the page. Each separate appendix
should be titled, and labeled by
a letter starting with A (e.g. Appendix A, Appendix B, etc.).
Appendices usually consist of
materials which are lengthy in nature and would make the report
difficult to read if included in
the main body of the report. Typical appendices are raw data,
sample calculations and long,
intricate procedures.
MIME 1650 Laboratory 3
Microscopy and Sample Preparation
Objective
The student should learn to prepare the sample and to use
microscopy to observe material
structures.
Agenda
• Laboratory 2 procedure (Team work)

• Use of microscopes and their nomenclature
• Methods of sample preparation
Procedures and Report Requirement
Read and follow the instruction when you start to work.
1. Cut sample.
1. Mount sample using pneumatic device.
2. Grind sample on coarse and fine grinding surfaces.
3. Polish sample.
4. Etch sample with natal.
5. Observe sample by using microscope. Sketch the
microstructure as completely as
possible in your report.
6. Use a polarizing filter on the microscope and observe the
grain structure.
7. After sketching the microstructure, measure the sample
surface roughness (set
‘cutoff’ 0.010, V-Pilotor).
Sample preparation
(Do Not Forget: You MUST Wear Safety Glasses in Lab!!!)
The sample used in material science microscopy usually has to
have a very flat surface. If
accurate structure is to be observed, care must be taken in

preparing the surface to avoid
unwanted scratches, heat effects and other forms of damage.
There are five major operations in the preparation of
metallographic specimens:
Sectioning, mounting (optional), grinding, polishing and
etching.
Sectioning
Sectioning, the removal of a conveniently sized, representative
specimen from a
larger sample, is the most important step in preparing specimens
for physical or
microscopic analysis. Incorrect preparation may alter the true
microstructure and
lead to erroneous conclusions.
Sectioning methods usually include sawing (using hacksaws,
band saws and wire
saws), abrasive cutting and electric discharge machining. In our
lab we use a
consumable-wheel abrasive cutting machine. It is often

performed using a
coolant, ensuring an almost plane surface without serious
mechanical or thermal
damage.
Procedure
1. To cut a suitable size, mark your specimen.
2. Use handles to adjust the specimen’s position.
3. Fix specimen rigidly
4. Cover the lid.
5. Push cutting and bump button.
6. Pull handle down slowly and apply proper pressure.
7. Push STOP button to finish cutting.
8. Remove specimen and clean cutting machine.
9. Remove any burrs and clean the sample by washing it.
Mounting
Mounting is often necessary in the preparation of specimens for
metallographic
study. Although bulk sample may not require mounting, small
or oddly shaped

specimens should be mounted to facilitate handling during
preparation and
examination.
Standard mounts usually measure 25 mm (1 inch), 32 mm (1.25
inch), or 38 mm
(1.5 inch) in diameter; mount thickness is often approximately
one half the mount
diameter.
How to do?
1. If MOLD BASE is in the bottom of MOLD CYLINDER,
rotate
RAM CONTROL to ‘UP’ position.
2. Position sample on MOLD BASE. For easy release, spray
little
lubricant on MOLD BASE in advance.
3. Rotate RAM CONTROL handle to ‘DOWN’ position.
4. Add mounting material – BAKELITE POWDER about 1
spoonful.
5. Insert and lock CLOSURE.
6. Rotate RAM CONTROL to ‘UP’ position. Apply pressure to
4200 psi (left mounting machine: the red point in middle line.

Right one: to Red Point) because the mount size is 1.25 inch.
Don’t exceed the Red point.
7. Put HEATER into MOLD CYLINDER. Turn on.
8. Rotate TIMER to 8-10 minutes.
9. Turn off HEATER. Use cooling cylinders immersed in water
10. Rotate RAM CONTROL to ‘NEUTRAL’ position. Allow
pressure to indicate zero.
11. Loosen CLOSURE
12. Raise Handle to vertical position. Keep one hand on Handle.
Rotate RAM CONTROL to ‘UP’ position.
13. Remove CLOSURE and mounted specimen with heat-
resistant
glove. Be careful, it may be ‘Hot’.
14. Immediately mark the sample for identification purposes.
Grinding
The purpose of grinding is to remove any surface damage
caused by cutting and
coarse grinding.
1. Coarse grinding: Chamfer the edges of the sample to 45° to
prevent

tearing of the lapping cloth. Grind the sample surface to remove
any
polymer residue. Clean the surface.
2. Fine grinding:
• Start with grit 240 abrasive paper which flat working surface
is
flooded with water.
• Hold sample face down and apply it proper pressure. Go
forward and backward against working surface of paper with
full strokes and without contacting with abrasive paper. Clean
it. Then rotate sample 90°, repeat until the last series of
scratches are removed (shown in Figure).
(This method is used for carbon steel)
1st 2nd 3rd
• Progressively fine grind with smaller grits, of 320, 400 and
600
size, washing the sample between each grinding.

Polishing
Use rotating wheels with a napless wet cloth. Put Al2O3
suspension on the polish
cloth. Turn on with Slow Speed. Be careful to hold sample.
Polish the sample
progressively using finer polishing particles. (Each wheel will
have on one size
polishing grit, either 0.3 or 0.05) After final polishing, wash
the sample under
running water and use a cotton swab and alcohol to dry the
sample (prefer to use
blower).
Etching
A polished sample frequently will not exhibit its microstr ucture,
because light is
uniformly reflected. To further reveal the microstructure, the
surface may need to
be etched. For ferrous sample, nital is commonly used. Nital is
a nitric acid and
alcohol mixture, and is highly toxic and corrosive.
• Put Nital to the polished surface of sample using a cotton

swap.
• Let Nital stay on surface about 30 – 40 seconds.
• Rinse off using running water.
• Use Methyl Alcohol (Methanol) to dry it.
Now the sample is ready for microscopy. Take care to protect
the surface. Never touch
the surface or carry the sample in your pocket.
Surface Roughness ( µm )
Drawing of sample under microscope:
MIME 1650 Laboratory 2
Resistance Spot Welding (RSW) Test
Please keep your welded sample for future laboratories.
Objective
The student learns the basic knowledge about resistance spot
welding and welds a
specimen for future laboratories.

Agenda
-Introduction to RSW Machine
-Laboratory 2 procedure
Equipment and tools
-Resistance Spot Welding Machine
-Micrometer -Steel Ruler
-Vernier Caliper -Marker (Scriber)
-Protective screen
Sample Low Carbon Steel Sheet
Lab Executants Individual
Lab Period 1 week
Report Individual
Location NE-1100 (Groups first meet TA’s in NE 1061)
Introduction
Resistance spot welding (RSW) is one of the most important
joining techniques. It is a
very rapid and economical process, extremely well suited to
automotive industry.
In RSW, both heat and pressure are used to affect coalescence.
The heat is the

consequence of the electrical resistance if the work piece and
the interface between them.
The pressure is varied throughout the weld cycle. A certain
amount of pressure is applied
initially to hold the workpiece in contact and thereby control
the electrical resistance at
the interface. When the proper temperature is attained, the
pressure is increased to
facilitate coalescence. Usually the required temperature can be
attained and coalescence
achieved in a few seconds or less.
The heat for RSW is obtained by passing a large electrical
current through the
workspaces for a short period of time. The amount of heat can
be determined by the basic
relationship:
RtIH
2
=
Where H is the total heat input, I is the current, R is the
electrical resistance of the circuit,
and t is the length of time in which current is flowing. It is

important to note that the
workpieces form part of the electrical circuit, and the total
resistance between the
electrodes consists of three components:
1. The resistance of the workpieces
2. The contact resistance between the electrodes and the
workpiece
3. The resistance between the surface to be joined, known as
faying surface
Figure 1 Spot-Welding Machine
The objective of RSW is to simultaneously bring both of the
faying surfaces to the proper
temperature while keeping the remaining material and the
electrodes relatively cool. The
electrodes are usually water-cooled to keep their temperature
low and to aid in keeping
them in proper condition.
As shown in Figure 2, the overlapping workpiece is positioned
between water-cooled

electrodes, which have reduced areas at the tips to produce
welds that are usually from
1/16 to ½ in. (1.5 to 13 mm) in diameter. After the electrodes
are closed on the
workpiece, the controlled cycle of pressure and current is
applied, producing a weld at the
metal interface. The electrodes then open and the workpiece is
removed.
A satisfactory spot weld, such as the one shown in figure 3,
consists of a nugget of
coalesced metal formed between the faying surfaces. Figure 4
shows the RSW’s squeeze,
weld, hold and off time.
There should be little indentation of the metal under the
electrodes. The strength of the
welds should be such that, in a tensile or tear test, the weld will
remain intact and failure
will occur in heated affected zone (HAZ) surrounding the
nugget. If proper current
density and timing, electrode shape, electrode pressure, and
surface conditions are

maintained, sound spot welds can be obtained with excellent
consistency.
Figure 2 The Scheme of RSW
Figure 3 A Spot Weld
Experimental Procedure
1. Measure the coupon size (length, width and thickness) Data
Sheet 1
2. Mark out the spot-weld location at 1′′ from each edge of the
sheet coupon along
the line.
3. At the welding machine, check if the electrodes are fitted and
aligned properly.
4. Switch on the red water supply valve located below the weld
controller.
5. Connect Air hose to the machine.
6. Switch on the power knob on the Weld Control Unit (WCU).
7. On the door of WCU ensure that
• Schedule #7 is selected
• The red Control Stop knob is in released position.
• The ‘DAS’ knob is in “Bypass” mode
• The knob for welding must be on No Weld.
8. Wait till the Hand Held Terminal (HHT) initializes. It should
show the display
record the previously made weld.

9. On the HHT, press ‘Program Mode’/‘F1’ (Review
Schedule)/‘F2’ (to change
Schedule#)/‘07’ (to select Schedule #)/‘Enter’
10. Check the weld schedule parameters. The parameters are:
Current 10KA, Cycle 10, Electrode Force (lbs) 800
Electrode tip Diameter 5mm
11. To change the weld parameters:
• Take the cursor key on the HHT to select the function you
want to modify.
• Enter the new values.
• Press ‘F3’ to download changes.
• Press ‘Enter’ twice to save changes to WCU#00, and Schedule
#7.
12. Place the coupon at the point you want to weld and operate
the machine in No
Weld.
13. Adjust the position of the coupon so as to get the weld at
the correct location.
14. Turn the Weld/No Weld knob to Weld.
15. Set protective screen for safety.
16. Make welds (two welds on one coupon) at the marked
locations. See if expulsion
occurs.
17. Go HHT, press “Display Mode/F1/Weld Data” and view and
record the welding

data.
Figure 4 Schematic diagrams of RSW Stages
Data Sheet
1. Specimen Size Date:
1
st
Measure 2
nd
Measure 3
rd
Measure Average
Sheet 1 Length
Sheet 2
Sheet 1 Width
Sheet 2
Sheet 1 Thickness
Sheet 2

2. Welding Records
Squeeze. ………cycle; Hold….…..cycle
Current
Actual
Setting Max Min Average
Weld
Cycle
Electrode
Force
Expulsion
(Yes/No)
Comment
Weld#1
Weld #2

1 mime 1650 materials science & engineering spring 2

1 mime 1650 materials science & engineering spring 2

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