Engineering Materials and their Properties
Atomic structure and diffusion within materials
To pass this assignment, you must show that you can
Revise material classification, examine atomic structure, explore atomic a
angements and assess imperfections in the atomic a
angement
Analyse movement of the atomic structure by diffusion
Investigate the practical applications of diffusion in processing material
PASS
All tasks within this section should be combined into a single report that is appropriately structured and referenced throughout. The final length of the report should be at least 1500 words.
1.1
Revise material classification
This section of the report should include:
1. A description of the four main categories into which materials can be placed.
2. A description of the physical and mechanical properties that materials in these categories possess.
3. In each category give an example material, define its properties and give a practical engineering application in which the material is used and a reason why the material was chosen for this purpose.
1.2
Examine atomic structure
This section of the report requires you to:
1. Using the Bohr model of an atom, show how one atom of phosphorus can be represented and give its electron configuration.
2. Explain how the three types of primary bonding in materials occur, in each instance given an example of two materials bonding in this way.
3. determine the number of covalent bonds that are possible for atoms of ca
on.
1.3
Explore atomic a
angements
This section of the report requires you to:
1. Explain what is meant by BCC, FCC and CPH crystal lattice structures.
2. For each type of lattice structure give an example material that has this structure and describe the properties this material exhibits.
3. Explain what is meant by the atomic packing factor and show that FCC has a higher atomic packing factor than BCC structures.
1.4
Assess imperfections in the atomic a
angement
This section of the report requires you to:
1. Explain what is meant by a dislocation in terms of defects in atomic a
angement.
2. Describe two types of dislocation defects within materials.
3. Give examples of three types of interfacial defects in materials.
This section should be completed as a separate short report and should contain at least 1000 words
1.5
Analyse movement of the atomic structure by diffusion
This short report requires you to:
1. Provide a description of the process of diffusion and the various mechanisms by which diffusion takes place in materials.
2. Explain which factors can affect the diffusion rate in materials and provide an analysis of how changing these variables impact the rate of diffusion.
3. A plate of iron is exposed to a ca
urising atmosphere on one side and a deca
urizing atmosphere on the other side at 700â—¦C. If a condition of steady state diffusion is achieved, calculate the diffusion flux of ca
on through the plate if the concentrations of ca
on at positions of 4 and 9 mm beneath the ca
urizing surface are 1.5 and 0.6, respectively.
Assume a diffusion coefficient of at this temperature.
This section should be completed as a separate short report and should contain at least 1250 words
1.6
Investigate the practical applications of diffusion in processing material
This short report requires you to:
1. Investigate and describe two engineering processes that require diffusion to take place.
2. Your description of the processes should include an overview of the process, including equipment and example materials used.
3. Within your investigation state how the parameters affecting the rate of diffusion can be altered and the impact this has on the process
. Engineering Materials and their Properties
Assignment 2: Inte
ogate mechanical properties of materials, and examine testing methods
To pass this assignment, you must show that you can
Examine mechanical testing techniques for common material properties, examine material deformation techniques and analyse impact of grain size, and grain size strengthening
Explore strengthening by solid solution strengthening
Conduct an analysis of the impact of dispersion strengthening
PASS
All tasks within this section should be combined into a single report that is appropriately structured and referenced throughout. The final length of the report should be at least 1500 words.
2.1
Examine mechanical testing techniques for common material properties
A
i) Describe the experimental equipment and procedure that would be required to perform a tensile test.
ii) Explain the mechanical properties that can be identified from the resulting stress vs. strain graph obtained from a tensile test.
B
Describe three types of hardness tests that can be ca
ied out on materials, explain how the hardness rating can be found in each case.
C
i) Explain the experimental procedure and equipment involved in a Charpy impact test.
ii) What properties of a material can be determined from the Charpy impact test?
2.2
Examine material deformation techniques
A
i) Explain the process of cold working a metal and discuss advantages and disadvantages of this process
ii) Fully describe the deformation mechanism of cold working explaining why it is more difficult to deform metals after cold working takes place.
B
i) Describe the three steps involved in the annealing process of a metal explaining how the structure of the metal changes in each case as well as the mechanical properties of the material.
2.3
Analyse impact of grain size, and grain size strengthening
A
i) Fully explain the impact that decreasing the grain size in materials has on the mechanical properties, explain why this is the case.
ii) Describe one way in which the grain size can be controlled, or refined.
2.4
Explore strengthening by solid solution strengthening
i) Explain what is meant by solid solution strengthening and describe the difference between substitutional solid solutions and interstitial solid solutions.
ii) Explain why interstitial atoms are more efficient at strengthening materials.
iii) Give four factors affecting the strength of a solid solution
iv) Alloying copper and nickel is one method of strengthening copper. Do some research and investigate the effects of alloying other metals with the CuNi alloy.
2.5
Conduct an analysis of the impact of dispersion strengthening
i) Explain what is meant by dispersion strengthened alloys and describe the mechanism behind this process.
ii) Conduct some research on oxide dispersion strengthened alloys and analyse the impact, on a specific example, that the oxide atoms have on the mechanical properties, compared to the original alloy or metal.
iii) For your chosen alloy in part ii) Give some applications that the strengthened alloy may have in an engineering context.
Engineering Materials and their Properties
Assignment 3 - Appraisal of engineering materials
To pass this assignment, you must show that you can
Examine fe
ous and non-fe
ous alloys and their uses, Examine ceramic materials and their uses, Examine Composite materials and their uses, Evaluate the use of photonic materials in advanced applications
Evaluate the use of photonic materials in advanced applications, Evaluate the existing material choice for a given engineering application
For a given engineering application, critically analyse and give justified recommendations for alternative material choices
PASS
All tasks within this section should be combined into a single report that is appropriately structured and referenced throughout. The final length of the report should be at least 1500 words.
3.1
Examine fe
ous and non-fe
ous alloys and their uses
This section of the report should include:
1. A discussion of some of the advantageous properties that fe
ous alloys possess.
2. A discussion of how changing the ca
on content in steel affects its properties and provide example engineering applications for types of steel in your discussion.
3. Give the distinctive features and limitations of aluminium, magnesium and their alloys, discuss applications for these materials.
3.2
Examine ceramic materials and their uses
This section of the report should include:
1. Discuss the structure of silicate ceramics and why silicate ceramics have great performance at extremely high temperatures.
2. Ceramics can be used in the aerospace industry due to their properties. Discuss the advantages and limitations of ceramic materials in this industry.
3.3
Examine polymers and their uses
This section of the report should include:
1. A discussion of the key differences in thermoplastics and thermosetting plastics.
2. Polymers can contain structures such as linear,
anched, crosslinked and network. Explain the differences in these structures and give example materials that have this structure.
3. The average molecular weight for the polymer polyethylene is 400,000 g/mol. Find the degree of polymerisation for this value. A repeating unit of polyethylene is given below.
4. A discussion of some of the properties and uses of polyethylene and some of the environmental considerations regarding this material.
3.4
Examine Composite materials and their uses
This section of the report should include:
1. An explanation of the key features and difference between particle reinforced composites and fi
e reinforced composites.
2. Give an example of a fi
e reinforced composite and some of the properties and applications this material has.
3. Explain what is meant by a sandwich structure composite and give an example of such a material and discuss some applications this material may have.
All tasks within this section should be combined into a single report that is appropriately structured and referenced throughout. The final length of the report should be at least 1200 words.
3.5
Evaluate the use of photonic materials in advanced applications
This section of the report should include:
1. Fi
e optic cables are cu
ently being used in communications. Provide a
ief discussion of how they transmit light and some of the principles behind this transmission of data.
2. Provide a discussion of the structure of a fi
e optic cable and suggest a suitable material for each component, justifying your answer.
3.6
Evaluate the existing material choice for a given engineering application
1. Consider the following scenario:
A
acket is to be designed so that it ca
ies electrical cables through the interior of an aircraft. The
acket needs to be designed so that it has a strength of at least 100MPa. It is also a requirement that they be as light as possible.
A suggested material is an aluminium alloy, using the Ashby plot below with the suggested guideline evaluate this choice of material and recommend another material choice, justifying your answer.
All tasks within this section should be combined into a single report that is appropriately structured and referenced throughout. The final length of the report should be at least 1000 words.
3.7
For a given engineering application, critically analyse and give justified recommendations for alternative material choices.
1. A pull up bar as a piece of gym equipment is to be designed. The equipment will be used for completing exercises that will put the frame under heavy load.
The problem may be simplified and modelled below:
The bar must be solid and cylindrical. It is required to be made of a material with a minimum Young’s modulus of 50GPa.
You may assume the deflection of the bar can be calculated from:
Where the moment of inertia I is:
The bar must be made from a material that minimises mass. You may consider the radius of the bar as the free variable.
A lead alloy has been initially suggested as the material for the frame. You must recommend two more suitable materials for the construction of this frame and fully justify your answer whilst considering cost and any environmental factors.
A suitable material chart has been provided to help with your task. You must show any working out you have done to come to your conclusions and include a material chart showing how you selected the materials.
Assignment 4 – Examine causes and protection against material failure
To pass this assignment, you must show that you can
Examine ductile and
ittle failure, Analyse the mechanism of creep in materials, Analyse fatigue in engineering structures, Analyse co
osion and wear and Analyse fracture and cracking
Calculate and apply stress concentration factors
Investigate and analyse methods used in an industrial application to protect against material failure
PASS
All tasks within this section should be combined into a single report that is appropriately structured and referenced throughout. The final length of the report should be at least 1500 words.
4.1
Examine ductile and
ittle failure
i) Fully describe the mechanisms behind
ittle and ductile fracture.
ii) Explain the difference between an engineering stress strain curve and true stress strain curve
4.2
Analyse the mechanism of creep in materials
i) Describe the 3 stages of creep.
ii) Describe 3 mechanisms of creep and explain the conditions for when each mechanism is dominant.
4.3
Analyse fatigue in engineering structures
i)
Label the stress range, stress amplitude and the mean, maximum and minimum stress.
ii) Explain how fatigue laboratory tests and S-N curves can be used to predict fatigue lives for materials.
iii) An 8mm diameter cylindrical rod fa
icated from a 1045 Steel is subjected to reversed tension compression load cycling along its axis. If the maximum tensile and compressive loads are +19kN and −19kN, respectively, determine its fatigue life. Assume that the stress plotted in the figure below is stress amplitude.
4.4
Analyse co
osion and wea
One-half of an electrochemical cell consists of