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Materials Selection Project

Selecting the “optimum” material for an application requires satisfying multiple parameters such

as:

• Physical Properties (mechanical, electrical, thermal, …)

• Manufacturability (conventional methods versus new methods)

• Cost (raw material, transportation, energy to manufacture, …)

• Availability (single source supplier, country of origin of raw material)

• Appearance (marketability of final product) • Performance requirements (resistant to corrosion,

fatigue, wear, …)

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Project 1- Materials Selection for Heating Element of Hair-dryer

A metal coil which is placed over a nonconductive material is used as the heating element of a

hairdryer. A sample is illustrated in Figure 1. This kind of resistor is called as wire wound

resistors and it consists of two parts. One is a cylindrical core which is generally made of

ceramic, fiberglass or plastic and the other is a high resistant metal wire. The main working

principle of this element is to convert the electrical energy into heat energy so as the air supplied

by fan passes it becomes warmer. Therefore, heating element should be a material with high

electrical resistivity to obtain more heat (ρe), and high melting temperature(Tm) to avoid melting

of the material at operating temperature which is around 40⁰C. When the temperature reaches a

certain value, a safety cut off switch prevents the temperature going any further. Regarding this,

maximum service temperature of the material can be defined as 80⁰C (Tmax). Furthermore, being

resistant to oxidation at high temperatures may be addressed as a preferable property for the

material. In addition to this, processability of the material is taken into consideration regarding

the hardness of the material.

(a) (b) (c)

Fig. 1 (a) Hair dryer sample, (b) Inside of a hair-dryer and (c) design requirement of the

heating element

In this project, wire used in the heating element should be investigated in terms of material

selection to improve the material properties of the heating element of hair-dryer and obtaining

much more light and cost effective design. Therefore, you are to select suitable material to meet

these functional requirements.

Functional requirement

High heating resistivity

(ρe) > 100 µΩ.cm

High service temperature

(Tmin), > 120oC

Being resistant to oxidation at

about 100oC

Low thermal conductivity ( )

Durability against

flammability

Processability (producing the

material as wire)

cost

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Project 2 - Materials Selection for Housing of Hair-dryer

The outer shell of hair-dryer houses and protects the fan, motor and heating element. It is

generally produced in L-shaped and its control switches are placed on the hand-hold portion in

order to adjust the system easily with hand while using the hair dryer. Being water-proof is very

important for casing, because if a hairdryer is dropped into a bathtub or sink and contact with the

water it may would short circuit and lead an electrical shock. Furthermore, weight of the housing

is extremely important in terms of being easy to handle during operation. Therefore, low density

(ρ), low thermal conductivity (λ), and being water proof and corrosion resistant are primary

criterions for housing.

In this project, the material used for the outer shell of hair-dryer should be investigated in terms

of material selection to improve the material properties of the housing of the hair-dryer and

obtaining much more light and cost effective design. Therefore, you are to select suitable

material to meet these functional requirements.

Functional requirement

low thermal conductivity (λ)< (W/K.m)

High service temperature (Tmin) >100⁰C

High fracture toughness(KIC)

Good Electricity Insulator

Durability

low density (ρ)< 2000 kg/m3

Mouldability

cost

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Project 3 - Materials Selection for Fan Blade of Hair-dryer

The fan works as a transformation mechanism which transforms the heated air outside of the

hairdryer and into the hair. The mechanical energy of the motor goes through the fans which are

connected to the motor. This mechanism helps the fans rotation about their axis. As a result of

this rotational movement, the air from the fan passes over the heating element, blowing the heat

from the coil to outside through the wet hair. Therefore, material which is used to form the fan

should be able to stand against high temperatures and be light-weight for easy use. So, high Tm

and low density (ρ) are preferable for the fan.

In this project, the material used for the fan blade of hair-dryer should be investigated in terms of

material selection to improve the material properties of the fan of the hair-dryer and obtaining

much more light and cost effective design. Therefore, you are to select suitable material to meet

these functional requirements.

Functional requirement

low density (ρ) <2000 kg/m3

High service temperature (Tmin) >100⁰C

Greater heat capacity (Cp)>1300J/Kg.K

Oxidation Resistance

Durability against flammability

Mouldability

cost

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Project 4 - Materials Selection for Jaw Crusher Liner

Modern trends in the design and the materials selection investigations for crushing rocks have

led to the development of a jaw crusher. The jaw crusher then enables its users to be able to

crush rocks into various sizes without using much man-power. Jaw crusher liner is used in jaw

crusher to give a wear protective surface for the machine. However, continuous usage causes

materials removal which intend reduces the performance/efficiency of the crusher liner.

Therefore, the purpose of this project is to find a suitable material for crusher liner that can

withstand the stated abrasive wear. As the only materials engineer at the Crusher Liner

Manufacturing Company, you have been asked to specify materials for a new liner that will be

able to meet the functional requirement.

By using Cambridge Engineering Software (CES) or Ashby Materials Selection Charts

combined with digital logic method, choose a list of candidate materials and compare to each

other in terms of general properties, mechanical properties, and processability. Produce

justification for your material selections.

.

Functional requirement

High toughness

High impact energy/damping capacity

Wear resistance/ Hard

Corrosion Resistance

Durability

castability

cost

Crusher

liner

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Project 5 - Materials Selection for fishing rod

It is clear that there are many requirements that a fishing rod needs to fulfill and materials

selection is crucial because for all of these requirements, each material must satisfy the

specification.

Rod Requirements Reason

The rod must be flexible This is so that the rod can be used to cast as well

as provide a type of suspension when there is

weight on the end of the line.

The rod must be rigid This is so it doesn‟t break under tension when

casting or playing a fish

The rod must be tough This is so cracks don‟t pass through it easily,

providing a long life.

The rod must be hard This is so the rod isn‟t indented easily if dropped

The rod must be water resistant This is because the rod is used in water

As the only materials/metallurgical engineering team at the Fishing Rod Manufacturing

Company, you have been asked to specify new materials for the fishing rod. The materials would

be substituted for currently used materials to achieve one or more of the following objectives:

lower cost; and light weight.

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Project 6 - Materials Selection for Water Tube

A tube is required for carrying water for domestic use. It is essential that the tubes have high

fracture toughness so that it doesn‟t crack quickly when exposed to the surface. Also, the tube

must not corrode when it is carrying chlorinated water. Currently, the material that is used

frequently is Polyvinyl chloride. However, this material usually burst when exposed.

Performance Requirement of the water pipe

Pipe requirement Reason

Flexible Be flexible enough to bend

Tough Be tough enough to not crack when car passes on the pipe [When an

underground pipe line is exposed, heavy cars pass on it and usually

breaks, This requires the pipe to be tough [high fracture toughness]]

Processability Must be easily shaped into tubes

water resistant When using it to carry water, the pipe almost always gets wet.]

Corrosion resistant It should not corrode when carrying chlorinated water

Cost The material must be cheap

As the only materials/metallurgical engineering team at Pipe Manufacturing Company, you have

been asked to specify new materials for the pipe to carry chlorinated water. The materials would

be substituted for currently used materials to achieve one or more of the following objectives:

lower cost; higher performance; and enhanced safety. Produce justification for your material

selections.

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Project 7 - Materials Selection for Heat Storing Wall

There are a number of schemes for capturing solar energy for home heating: solar cells, liquid

filled heat exchangers, and solid heat reservoirs. The simplest of these is the heat-storing wall: a

thick wall, the outer surface of which is heated by exposure to direct sunshine during the day,

and from which heat is extracted at night by blowing air over its inner surface (As shown below).

heat-storing wall.

An essential of such a scheme is that the time-constant for heat flow through the wall be about 10

hours; then the wall first warms on the inner surface roughly 10 hours after the sun first warms

the outer one, giving out at night what it took in during the day. We will suppose that, for

architectural reasons, the wall must not be more than 0.25 m thick. Select suitable materials that

maximize the thermal energy captured by the wall while retaining a heat-diffusion time of up to

10 hours.

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Project 8 - Material Selection for Helmet Visor

A material is required for the visor of a safety helmet to provide maximum facial protection.

To allow clear vision the visor must be optically transparent. To protect the face from the front,

from the sides, and from below, it must be doubly curved, requiring that the material can be

molded. We thus have two constraints: transparency and ability to be molded. Fracture of the

visor would expose the face to damage: “maximizing facial protection” therefore translates into

maximizing resistance to fracture. The material property that measures resistance to fracture is

the fracture toughness, KIC. The objective is therefore to maximize KIC.

As the only materials/metallurgical engineering team at the Helmet Visor Manufacturing

Company, you have been asked to specify new materials for the Helmet Visor. The materials

would be selected to achieve one or more of the following objectives: lower cost; and higher

fracture toughness. Use any of the methods discussed in class to select possible candidate

materials to meet these design requirements.

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Project 9 - Material Selection for Windings of an Electric Air-Furnace

A material is required for the windings of an electric air-furnace capable of temperatures up to

1000ºC. If the material is to be used as windings it must be able to be drawn to wire and wound

to a coil, requiring ductility. It must conduct electricity and be able to operate at 1000oC in air.

As the only materials/metallurgical engineering team at the Manufacturing Company, you have

been asked to specify new materials for the windings of an electric air-furnace. The materials

would be selected to achieve one or more of the following objectives: lower cost; and lower

resistivity. Use any of the methods discussed in class to select possible candidate materials to

meet these design requirements.

Functional requirement

High service temperature (Tmax) >1000⁰C

Able to be rolled or drawn to wire

Good electrical conductor

Some ductility so that it can be wound,

Good resistance to oxidation at elevated temperature

Cost

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Project 10 - Material Selection for Automotive Brake Disc

An automotive brake disc or rotor is a device for slowing or stopping the motion of a wheel

while it runs at a certain speed. The widely used brake rotor material is cast iron which consumes

much fuel due to its high specific gravity. The aim of this project is to select the optimum

material for the application of brake disc system emphasizing on the substitution of this cast iron

by any other lightweight material. The most important consideration is the ability of the brake

disc material to withstand high friction and less abrasive wear. Another requirement is to

withstand the high temperature that evolved due to friction. The brake disc must have enough

thermal storage capacity to prevent distortion or cracking from thermal stress until the heat can

be dissipated. Weight, manufacturing process ability and cost are also important factors that are

need to be considered during the design phase.

As the only materials/metallurgical engineering team at the Automotive Brake Disc

Manufacturing Company, you have been asked to specify new materials for the brake disc. The

materials would be selected to achieve one or more of the following objectives: lower cost; and

higher abrasive resistant. Use any of the methods discussed in class to select possible candidate

materials to meet these design requirements.

Functional requirement

High compressive strength

Withstand high friction

Wear resistance/ Hard

Thermal capacity

Low specific gravity

castability

cost

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Project 11 - Material Selection for Corn Mill Plate

Over 90% of all Ghanaians consume delicacies prepared from milled maize. Examples of such

delicacies are „banku‟, Akple‟, „kenkey‟, corn-porridge, among others. In Ghana maize (or corn)

is milled using two metal plates of cast iron and are produced by sand casting, the raw materials

being mainly metal scraps. The selection of metal scraps, their charging during the casting

operation, and the achievement of quality and reproducible products require knowledge and

understanding of the science and metallurgy. Prior research indicates that these locally-produced

milling plates have poor wear and corrosion resistance. Therefore, during milling, worn-out

metal debris intermix with the milled maize, making the latter unwholesome. Cast iron contains

at least 95% of elemental iron which consumed. It is clear from the above that there is the need

to improve the quality of the locally-produced milling plates in order to minimize or eliminate

the health risks associated with them.

As the only materials/metallurgical engineering team at the Corn Mill Manufacturing Company,

you have been asked to specify new materials for the corn mill plate. The materials would be

substituted for currently used cast iron to achieve one or more of the following objectives: lower

cost; and higher abrasive resistant. Also the material should be non-toxic, corrosion resistant and

fatigue resistant.

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Project 12 - Selection of Materials for the Structure

As the only materials/metallurgical engineering team at Structural Materials Company, you have

been asked to specify new materials for a structure (as shown below). The structure must be stiff,

strong, and cheap. Stiff, so that the building does not flex too much under wind loads, or internal

loading. It must be strong, so that there is no risk of it collapsing. Also, it must be cheap, because

such a lot of material is used. The structural frame of a building is rarely exposed to the

environment; and it is not, in general, visible. So criteria of corrosion resistance, or appearance,

are not important. The design goal is simple: strength and stiffness at minimum cost. The design

requirements for the floor beams are shown in the table below. Use any of the methods discussed

in class to select possible candidate materials to meet these design requirements.

Figure 1. A hypothetical building. Materials are used in three ways: for the structure, as cladding

and for the internals.

Table 1. Design requirements for floor beams

Function Floor beams

Objective Minimize the cost

Constraints (a) Length L specified

(b) Stiffness: must not deflect too much under design loads

(c) Strength: must not fail under design loads

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Project 13 - Material Selection for a Train Wheel

A rail tire is usually made from metallic materials, and is typically heated and pressed onto the

wheel, where it remains firmly as it shrinks and cools. Over the past few decades demand for

improved performance of trains has led to higher accelerations, speeds and braking forces which

have increased the stresses in the wheel/rail interface. The changing loads in the contact have a

large effect on the rail and wheel damage mechanisms, such as wear and rolling contact fatigue

(RCF), both of which are driven by the stress in the wheel/rail contact. Material choice can be

used to try to control the damage occurring at the interface, and over time more and more durable

wheel and rail materials have been developed. You are to select a suitable material that will give

the optimal system response. The wheels must be resilient, hard, wear resistant, rolling contact

fatigue resistant, high thermal conductivity, corrosion resistant and low friction coefficient.

Fig. 1 Surface damage due to surface initiated fatigue: a – railway-wheel contact; b – surface

damage of wheel tread resulting from surface-induced cracks; c – damage in rim

You are to list your design requirement and translate them to select a suitable material for the

railway wheel.

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Project 14 - Material for an ultra-high powered laser window

The window through which the beam emerges from a high-powered laser must obviously be

transparent to light. Even then, some of the energy of the beam is absorbed in the window and

can cause it to heat and crack. This problem is minimized by choosing a window material with a

high thermal conductivity λ (to conduct the heat away) and a low expansion coefficient α (to

reduce thermal strains). You are to select a suitable window material that will give the optimal

value of

M = ⁄

Use the – chart to identify the best material for an ultra-high powered laser window.

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Project 15 – Material Selection for Springs for trucks

In vehicle suspension design it is desirable to minimize the mass of all components. You have

been asked to select a material and dimensions for a light spring to replace the steel leaf-spring

of an existing truck suspension. The existing leaf-spring is a beam, shown schematically in the

figure below. The new spring must have the same length L and stiffness S as the existing one,

and must deflect through a maximum safe displacement max without failure. The width b and

thickness t are free variables.

You will need the equation for the mid-point deflection of an elastic beam of length L loaded in

three-point bending by a central load F:

and that for the deflection at which failure occurs

where I is the second moment of area; for a beam of rectangular section, I=b /12 and

E and σf are the modulus and failure stress of the material of the beam.

Derive a material index for the selection of a material for this application. Note that this is a

problem with two free variables: b and t; and there are two constraints, one on safe deflection

and the other on stiffness S. Use the two constraints to fix free variables. The table catalogs

the requirements:

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Project 16 – Materials Selection for Rotary Lawn-Mower

A material is required for the blade of a rotary lawn-mower. Cost is a consideration. For safety

reasons, the designer specified minimum fracture toughness for the blade: it is K1C > 30

MPa.m1/2

. The other mechanical requirement is for high hardness, H, to minimize blade wear.

Hardness, in applications like this one, is related to strength:

H = 3σy

where σf is the strength. Use the K1C–σf chart to identify three materials that have K1C > 30

MPa.m1/2

and the highest possible strength. To do this, position a „„K1C‟‟ selection line at 30

MPa.m1/2

and then adjust a „„strength‟‟ selection line such that it just admits three candidates.

Use the Cost chart to rank your selection by material cost, hence making a final selection.

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Project 17 - Material for Furnace Insulation

A furnace is required to sinter powder-metal parts. It operates continuously at 650C while the

parts are fed through on a moving belt. You are asked to select a material for furnace insulation

to minimize heat loss and thus to make the furnace as energy-efficient as possible. For reasons of

space the insulation is limited to a maximum thickness of x = 0.2 m. List the function,

constraints, objective and free variable.

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Project 18 – Materials Selection for Eye Lenses

A contact lens is a lens worn in front of the eye, mainly used to treat myopia, hyperopia,

astigmatism, and presbyopia. Glasses or “spectacles” are worn on the face a short distance in

front of the eye. Contact lenses are worn directly on the surface of the eye. Up until the late

1970s, contact lenses were made from two materials. Hard contact lenses were made of

polymethyl methacrylate (PMMA), while the soft contact lenses were made of a hydrated

polymer, hydroxyethylmethacrylate (HEMA), which contained 37.8% water by weight. These

lenses provided clear vision and comfort, but there was a problem. These lenses did not allow

oxygen to reach the cornea. Because of this, the cornea could change, adversely, in some contact

lens wearers. As a materials engineer who is working at Eye Lenses Manufacturing Company,

you have been tasked to select material for eye lens that will allow oxygen to pass through (i.e. y

hydrophobic materials with high oxygen permeability). In addition, the material for the eye lens

should have the following properties: (i) easy manufacturing, (ii) must be transparent, (iii) light

(low density), (iv) cheap (reasonable price), (v) bio compatible, (vi) medium fracture toughness,

(vii) lower elastic modulus.

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Project 19 – Materials Selection for Connecting Rod in a High-Performance Engine

A connecting rod in a high-performance engine is a critical component: if it fails, catastrophe

follows. Yet to minimize inertial forces and bearing loads it must weigh as little as possible,

implying the use of light, strong materials, stressed near their limits. When minimizing cost is the

objective, connecting rods are frequently made of cast iron because it is so cheap. When cast iron

is used it does not provide the maximum performance. As a metallurgical/materials engineer,

you are to select the best materials for connecting roads when the objective is to maximize

performance?

The design requirements for a connecting rod of minimum weight with two constraints: that it

must carry a peak load F without failing either by fatigue or by buckling elastically. For

simplicity, assume that the shaft has a rectangular cross-section A = bw.

Design Requirement: Connecting Rods

Function Connecting rod for reciprocating engine

Constraints Must not fail by high-cycle fatigue

Must not fail by elastic buckling

Stroke, and thus connecting rod length L, specified

Objective Minimize mass

Free variables Cross section A

Choice of material

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Project 20 – Materials Selection for Brake Caliper

The brake caliper can be idealized as two beams of length L, depth b, and thickness h, locked

together as their ends. Each beam is loaded in bending when the brake is applied, and because

braking generates heat, it gets hot. The lower schematic represents one of the beams. Its length L

and depth b are given. The beam stiffness S is critical: if it is inadequate the caliper will flex,

impairing braking efficiency and allowing vibration. Its ability to transmit heat, too, is critical

since part of the heat generated in braking must be conducted out though the caliper. The design

requirements are summarized in the table below.

The mass of the caliper scales with that of one of the beams.

A schematic of a brake caliper. The long arms of the caliper are loaded in bending and must

conduct heat well to prevent overheating.

You have been asked to select a suitable material for the brake caliper to meet the design

requirements.

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Structure of the Report

The 8 - 12-page format consists of the following sections (which may be renamed if

appropriate):

o Title

The title of the project in 14 pt bold.

o Attribution

Write the names of the team members, with all initials just below the title; The names

should be (bold)

The university‟s name, with full address;

o Abstract Try for one sentence each on motivation, objective, method, key results, discussion,

conclusions.

Don‟t exceed 3 sentences on any one of the above points.

Try not to exceed 100 words. Imagine that you are paying 2 cedis a word “The reader

of an Abstract has been lured by the title (if it is a good one). He or she now wants to

know whether to read on. Tell them, in as few sentences as possible, what they will

find. No waffle, no spurious details. Try not to exceed 100 words.”

o Background on design

Present relevant background and literature review for your topic.

The problem statement for your selected topic. Define your project.

Outline your objectives or goals for the project. Example: Identify promising

candidate materials for a given design

o Describe material selection process

Function, objectives, etc.

Possible material Index/Indices, showing calculation method and define all

symbols and units.

Application of Digital Logic Method

What materials were eliminated? Why?

Do these indicate other criteria that should be included in the analysis?

How were multiple objectives or constraints balanced?

o Results and discussion

Show outputs from CES software

What 3-5 materials were identified as promising?

Summarize pertinent material properties and processing characteristics

Discuss what you think are the strengths and weaknesses of each candidate

How do these compare with materials used in actual designs?

o Summary and Concluding Remarks

Describe any other information or analysis you would need to make a final

selection

Speculations and recommendations may be summarized as necessary.

Finally, reasons for the selected materials shall be substantiated.

o References List all the publications used for the term project.

A reference mustn‟t be listed if it is not used in the text. In the list, references are

indicated numerically.

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They must be given in the text in the same order as they are listed in References

section.

EXTREMELY IMPORTANT: 1) Use this project as a platform to explore/display your innovative side by

suggesting/analyzing your genuine design/material selection project.

2) Be aware that PLAGIARISM may get you expelled from the university. Copying

a text directly from an article without giving it in quotations (even if a reference

number is given) is plagiarism. DO NOT DIRECTLY COPY (STEAL)

INFORMATION. REWORD/REPHRASE IT. MAKE IT YOUR OWN.

3) Be clear and concise in your writing. Dumping unnecessarily long information

WILL NOT earn you any credit.

4) Explain figures/tables and refer to them in the text appropriately to help readers

understand your text better. Do not give a figure or table if not explained in the

text. Tell the reader what the figure/table shows and why you are using it.

5) Use A4 size paper with the following page margins: Left=25mm; Right=20mm;

Top=25mm; Bottom=20mm. Use font “Times New Roman”, font size of 11, and

line spacing of 1. Insert page numbers at bottom right.