dr. emmanuel kwesi arthur - materials quality control ......dr. emmanuel kwesi arthur email:...
TRANSCRIPT
Materials Quality Control,Assurance and Selection
Dr. Emmanuel Kwesi Arthur
Email: [email protected]
Phone #: +233541710532
Department of Materials Engineering,
Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
©2019
Course Code: MSE 456
1
Lecture Four
Demo
The chart-management tool bar
Box selection
tool
Cancel
selection
Add text
Zoom
Add
envelopes
Un-zoom
Black and white
chart
Hide failed
materials
Grey failed
materials
Line selection
tool
Exercise: selecting light, strong materials (1)
4.1 The material index for selecting
light strong materials is
M =
where is the yield strength and
the density.
Make a Graph stage with these
two properties as axes
Impose a selection line (slope 1)
to find materials with the highest
values of M.
Add a Limit stage to impose the
additional constraint:
Elongation > 10%
/y
y
Results: Age-hardening wrought Al-alloys
Nickel-based superalloys
Titanium alloys
Wrought magnesium alloys
Browse Select SearchBrowse Select Search
1. Selection data
Edu Level 2: MaterialsEdu Level 2: MaterialsEdu Level 2: MaterialsEdu Level 2: Materials
2. Selection Stages
Graph Limit Tree
2. Selection Stages
Graph Limit Tree
Density
Str
en
gth
y
1
yHigh
Density
Str
en
gth
y
1
yHigh
Density
Modulus
Strength
Elongation
etc
10
Density
Modulus
Strength
Elongation
etc
10
Min Max
Exercise: selecting light, strong materials (2)
4.2 Repeat the selection of 4.1, but use the
Advanced facility to make a bar-chart with
the index
M =
on the Y-axis.
Impose a Box selection to find materials
with the highest values of M.
Add a Limit stage to impose the additional
constraint:
Elongation > 10%
/y
Ind
ex
y /
yHigh
Browse Select SearchBrowse Select Search
1. Selection data
Edu Level 2: MaterialsEdu Level 2: MaterialsEdu Level 2: MaterialsEdu Level 2: Materials
2. Selection Stages
Graph Limit Tree
2. Selection Stages
Graph Limit Tree
Density
Modulus
Strength
Elongation
etc
10
Density
Modulus
Strength
Elongation
etc
10
Min Max
List of properties Density
Modulus
Yield strength
etc
+ - */ ^ ( )
Yield strength /
Density
List of properties Density
Modulus
Yield strength
etc
+ - */ ^ ( )+ - */ ^ ( )
Yield strength /
Density
Exercise: selecting materials for springs (1)
4.3 A material is required for a spring that may be
exposed to shock loading, and must operate in
fresh and salt water.
Constraints:
Fracture toughness > 15 MPa.m1/2
Very good durability in fresh and salt water
Objective:
Maximise stored elastic energy
y
Strain
Str
es
s
E2
1
2
12y
yy
Elastic energy
The best materials for
springs are those with the
greatest value of
the index
E
2y
Make a graph with
Young’s modulus E on the X-axis
Yield strength on the Y-axis
Put on a line of slope 0.5 (corresponding to power 2)
Select materials above the line
Add the other constraints using a limit stage
y
Browse Select SearchBrowse Select Search
1. Selection data
Edu Level 2: MaterialsEdu Level 2: MaterialsEdu Level 2: MaterialsEdu Level 2: Materials
2. Selection Stages
Graph Limit Tree
2. Selection Stages
Graph Limit Tree
Modulus ES
tre
ng
th
y
0.5
E
2y
High
Modulus ES
tre
ng
th
y
0.5
E
2y
HighDensity
Fr. toughness
etc
Fresh water
Salt water
Min Max
15
v. good
v. good
Density
Fr. toughness
etc
Fresh water
Salt water
Min Max
15
v. goodv. good
v. goodv. good
Exercise: selecting materials for springs (2)
4.4 Repeat the selection of 4.3, but use the
Advanced facility to make a bar-chart with
the index
on the Y-axis.
.
E/2y
Ind
ex
y2
/E E
2y
High
Plot the bar chart
Use a box selection to select the materials
with high values of the index
Add the other constraints using a limit stage
Results: CFRP, epoxy matrix (isotropic)
Nickel-based superalloys
Titanium alloys
Browse Select SearchBrowse Select Search
1. Selection data
Edu Level 2: MaterialsEdu Level 2: MaterialsEdu Level 2: MaterialsEdu Level 2: Materials
2. Selection Stages
Graph Limit Tree
2. Selection Stages
Graph Limit Tree
Density
Fr. toughness
etc
Fresh water
Salt water
Min Max
15
v. good
v. good
Density
Fr. toughness
etc
Fresh water
Salt water
Min Max
15
v. goodv. good
v. goodv. goodList of properties Density
Modulus
Yield strength
etc
+ - */ ^ ( )
(Yield strength^2)/
Young’s modulus
List of properties Density
Modulus
Yield strength
etc
+ - */ ^ ( )+ - */ ^ ( )
(Yield strength^2)/
Young’s modulus
Quiz 3
1. Use the modulus–density chart to find, from among the materials that appear on it:
(a) The material with the highest density.
(b) The metal with the lowest modulus.
(c) The polymer with the highest density.
(d) The approximate ratio of the modulus of woods measured parallel to the grain and perpendicular to the grain.
(e) The approximate range of modulus of elastomers.
Quiz 3
Exercise 2
1) Make an E–ρ chart using the CES software. Use a box selection to find three materials with densities between 1000 and 3000 kg/m3 and the highest possible modulus.
2) Data estimation. The modulus E is approximately proportional to the melting point Tm in Kelvin (because strong inter-atomic bonds give both stiffness and resistance to thermal disruption). Use CES to make an E–Tm chart for metals and estimate a line of slope 1 through the data for materials. Use this line to estimate the modulus of cobalt, given that it has a melting point of 1760 K.
3) Sanity checks for data. A text reports that nickel, with a melting point of 1720 K, has a modulus of 5500 GPa. Use the E–Tm correlation of the previous question to check the sanity of this claim. What would you expect it to be?
Exercise 3
1) Explore the potential of PP–SiC (polypropylene–silicon carbide) fiber composites in the following way. Make a modulus–density (E–ρ) chart and change the axis ranges so that they span the range 1 < E <1000 GPa and 500 < ρ < 5000 kg/m3 . Find and label PP and SiC, then print it. Retrieve values for the modulus and density of PP and of SiC from the records for these materials (use the means of the ranges).
2) Use a ‘Limit’ stage to find materials with modulus E > 180 GPa and price Cm < 3 $/kg.
3) Use a ‘Limit’ stage to find materials with modulus E > 2 GPa, density ρ < 1000 kg/m3 and Price < 3/kg.
Exercise 4
1) Make a bar chart of modulus, E. Add a tree stage to limit the selection to polymers alone. Which three polymers have the highest modulus?
2) Make a chart showing modulus E and density ρ. Apply a selection line of slope 1, corresponding to the index E/ρ positioning the line such that six materials are left above it. Which are they and what families do they belong to?
3) A material is required for a tensile tie to link the front and back walls of a barn to stabilize both. It must meet a constraint on stiffness and be as cheap as possible. To be safe the material of the tie must have a fracture toughness K1c > 18 MPa.m1/2. The relevant index is
Assignment 2
1) Construct a chart of E plotted against Cm ρ. Add the constraint of adequate fracture toughness, meaning K1c > 18 MPa.m1/2, using a ‘Limit’ stage. Then plot an appropriate selection line on the chart and report the three materials that are the best choices for the tie.
Example 2: Stiff & Light Tension Members
Example 2: Stiff & Light Tension Members
Assignment 3
1) List the six main classes of engineering materials. Use your own experience to rank them approximately:`
(a) By stiffness (modulus, E).
(b) By thermal conductivity (λ).
1) What are the steps in developing an original design?
2) Describe and illustrate the ‘translation’ step of the material selection strategy.
3) What is meant by an objective and what by a constraint in the requirements for a design? How do they differ?
4) You are asked to design a fuel-saving cooking pan with the goal of wasting as little heat as possible while cooking. What objective would you choose, and what constraints would you think must be met?
Assignment 4
a) Sprint bikes.
b) Touring bikes.
c) Mountain bikes.
d) Shopping bikes.
e) Children’s bikes.
f) Folding bikes.
Use your judgement to identify the primary objective and the constraints that must be met for each of these.
Bikes come in many forms, each aimed at a particular sector of the market:
Quiz 4
Examine the material property chart of modulus versus density. By what factor are polymers less stiff than metals? Is wood denser or less dense than polyethylene (PE)?
Example 3: Cheap Stiff Column
A column supports compressive
loads e.g. legs of a table or pillars
The goal is to identify the cheapest
materials that will support the load
without failing
19
Cheap Stiff Column
The objective function is cost
The buckling constraint is given by (safe design)
Noting that I = r4/4 = A2/4 and eliminating the
variable A gives
The material index for a low cost column that resists
buckling is
Performance of Stiff but Cost Effective Column
Slope=2
Quiz 5
1) Use the modulus–relative cost chart to find, from among the materials that appear on it:
(a) The cheapest material with a modulus greater than
1 GPa.
(b) The cheapest metal.
(c) The cheapest polymer.
(d) Whether magnesium alloys are more or less expensive than aluminum alloys.
(e) Whether PEEK (a high-performance engineering polymer) is more or less expensive than PTFE.
Quiz 5
Assignment 5
Pick any three engineering applications and answer thefollowing:
1. Determine required properties: ex: mechanical,electrical, thermal,
magnetic, optical, deteriorative.
2. Express the design requirements into functions andobjectives.
3. Properties: identify candidate materials
4. Material: identify required ProcessingProcessing: changes structure and overall shapeex: casting, sintering, vapor deposition, dopingforming, joining, annealing.
QUESTIONS