1.1 Materials And Their Applications Flashcards
(102 cards)
1
Q
What is the definition of a manufactured board ?
A
A man-made, wood-based composite material
2
Q
What is the definition of a stock form?
A
A set of standard sizes in which materials are available, as well as the format e.g. powders, granules, sheets etc.
3
Q
What is the definition of mechanical properties?
A
Associated with how a material reacts to an external force
4
Q
What is the definition of physical properties?
A
Associated with the actual make-up or structure of the material.
5
Q
What is the definition of compressive strength?
A
The ability to withstand being crushed or shortened by pushing forces
6
Q
What is the definition of tensile strength?
A
The ability to resist stretching or pulling forces.
7
Q
What is the definition of hardness?
A
The ability to resist abrasive wear such as scratching, surface indentation or cutting.
8
Q
What is the definition of toughness?
A
The ability to absorb impact force without fracture.
9
Q
What is the definition of a composite material?
A
A material comprised of two or more different materials, resulting in a material with enhanced properties
10
Q
What is the definition of a smart material?
A
A material whose physical properties change in response to an input or change in the environment, such as electricity, pressure, temperature or light.
11
Q
What is the definition of a modern material?
A
A material developed through the invention of new or improved processes, for example as a result of man-made materials or human intervention
12
Q
What is the definition of a ferrous metal?
A
A metal containing mostly iron and carbon
13
Q
What is the definition of a non-ferrous metal?
A
A metal which does not contain iron.
14
Q
What is the definition of an alloy?
A
A metal made of two or more metals, or combing two or more elements, one of which must be metal.
15
Q
What is the definition of a thermoplastic?
A
A material that can be repeatedly reheated and reshaped
16
Q
What is the definition of a thermosetting polymer?
A
A material which when heated undergoes a chemical change whereby the molecules form rigid cross links. Thermosetting polymers can’t be reheated and reshaped, even at high temperatures.
17
Q
What stock forms do metals have ?
A
Square tubing
Square bar
Round tubing
Round bar
Hexagonal bar
18
Q
What are the advantages of using stock forms ?
A
Uniformity of material across countries
The materials form can be transported more easily once converted into stock forms rather than as a raw materials
Standard stock sizes are less expensive than specialist sizes because they are processed in large quantities and there is less waiting time than for a specialist size as the material will be repeatedly manufactured in the same sizes.
19
Q
What is bending strength ?
A
The ability to resist forces that may bend the material.
20
Q
What is shear strength ?
A
The ability to resist sliding forces on a parallel plane
21
Q
What is torsional strength?
A
The ability to withstand twisting forces from applied torque or torsion.
22
Q
What is plasticity ?
A
The ability to be permanently deformed (shaped) and retain the deformed shape.
23
Q
What is ductility?
A
The ability to be drawn out under tension, reducing the cross-sectional area without cracking, for example stretching a material into wire.
24
Q
What is malleability?
A
The ability to withstand deformation by compression without cracking.
Malleability increases with a rise in temperature.
25
What is elasticity?
The ability to be deformed and then return to the original shape when the force is removed.
26
What is an electrical conductor ?
Allows the flow of electrical current through the material.
A good conductor gives very little resistance to the flow of charge.
27
What is an electrical insulator?
Does not allow the flow of electricity through the material.
28
What is a thermal conductor ?
Allows the transfer of heat energy through the material.
A material with high thermal conductivity allows the transfer of heat to occur quickly across the material.
29
What a thermal insulator ?
Prevents the transfer of heat through the material.
30
What is thermal expansion?
The increase in material volume in response to a heat input.
31
What is an opaque material?
Prevents light travelling through.
32
What is a translucent material?
Allows light through but diffuses the light so that objects appear blurred.
Frosted glass is an example of a translucent material.
33
What is a transparent material?
Allows light to pass through easily which means you can see clearly through the material.
34
What is density?
The mass of the material in a standard volume of space.
35
What is fusibility?
The ability of the material to be fused or converted from a solid to a liquid or molten state, usually by heat.
Good fusibility is an essential property for a metal being cast.
36
What is magnetism?
The natural force between objects that causes the material to attract irons or steels.
37
What is corrosion/degradation resistance ?
The ability of the material to withstand environmental attack and decay.
38
What are the 7 groups that materials can be classified into?
1. Metals
2. Woods
3. Polymers
4. Papers and boards
5. Composites
6. Smart materials
7. Modern materials
39
What 3 categories can metals be classified ?
Ferrous
Non-ferrous
Alloy
40
What are some examples of ferrous metals?
Low carbon steel
Medium carbon steel
Cast iron
41
What are some examples of non-ferrous metals?
Aluminium
Copper
Zinc
Silver
Gold
Titanium
Tin
42
What are some examples of ferrous alloys?
Stainless steel
Die steel (tool steel)
43
What are some examples of non-ferrous alloys?
Bronze
Brass
Duralumin
Pewter
44
What type of metal will rust?
Ferrous
45
What type of metals are magnetic ?
Ferrous
46
What type of metal is not magnetic?
Non-ferrous
47
What type of metal will not rust?
Non-ferrous
48
What are hardwoods?
A wood from deciduous trees.
These trees are generally slow growing and lose their leaves in autumn
49
What are the hardwoods?
Oak
Ash
Mahogany
Teak
Birch
Beech
50
What is a softwood?
A wood from a coniferous tree.
These trees are generally fast growing and tend to be evergreen
51
What are the softwoods?
Pine
Spruce
Douglas fir
Redwood
Cedar
Larch
52
What is a manufactured board?
A man-made wood-based composite materials.
Manufactured are available in much larger sizes than solid wood.
53
What are the manufactured boards?
Plywood
Marine plywood
Aeroply
Flexible plywood
Chipboard
MDF
54
What is a thermoplastic ?
A material which be repeatedly rebated and reshaped,allowing it to be recycled after its initial use.
55
What is the structure of thermoplastics ?
They have long linear chain molecules held be van de Walls forces.
56
What are the thermoplastics ?
Low density polyethylene (LDPE)
High density polyethylene (HDPE)
Polypropylene (PP)
High impact polystyrene (HIPS)
Acrylonitrile butadiene styrene (ABS)
Polymethyl methacrylate (PMMA/acrylic)
Polyethylene terephthalate (PET)
Nylon
Polyvinyl chloride (PVC)
57
What is a thermosetting polymer?
A material which when heated undergoes a chemical change whereby the molecules form rigid cross links.
Thermosetting polymers cannot be reheated and reshaped, even at very high temperatures.
58
What are the thermosetting polymers ?
Urea formaldehyde (UF)
Melamine formaldehyde (MF)
Polyester resin
Epoxy resin
59
What is an elastomer?
A material which at room temperature can be deformed under pressure and then upon release of the pressure, will return to its original shape.
60
What is the structure of elastomers?
They have weak bonds which allow them to stretch easily. They can be stretch repeatedly and upon immediate release of the stretch, will return with force to the original length.
61
What are the elastomers?
Natural rubber
Polybutadiene
Neoprene
Silicone
62
Why is polyethylene terephthalate suitable for a drinks bottle ?
It is a thermoplastic which allows to be recycled; this is important for a single use plastic as it means it will not contribute to landfill.
It is tough - if the user drops the bottle , the contents will not be released.
It is available in a transparent form, which allows the user to see how much drink if left.
It is impermeable to carbon dioxide, making it ideal for carbonated drinks
63
Why is melamine formaldehyde suitable for a kitchen worktop?
It is a thermosetting polymer with a high melting point, so it will not be affected by hot pans placed on the surface.
It is chemical resistant, which allows the worktop to be cleaned with detergent.
It is hard, which enables the user to clean the surface with a scouring pad without scratching the surface.
It can be pigmented to give the kitchen worktop a specific colour to fit the kitchen aesthetics.
64
Why is neoprene suitable for a wetsuit?
It is an elastomer so the wetsuit will stretch and release to fit tightly around the body.
It has good degradation resistance so will not be damaged by salt water in the sea.
It can be pigmented to given a particular colour choice for the customer, or to provide a company brand colour option.
65
What are papers and boards ?
They can be described as compliant materials, meaning that they can be scored, folded and cut with basic tooling to form items such as nets for packaging.
66
What are some examples of papers and boards?
Layout paper
Cartridge paper
Tracing paper
Bleed proof paper
Watercolour paper
67
What is a composite material ?
A material comprised of two or more different materials, resulting in a material with enhanced properties.
68
What are the 3 types of composite material?
Fibre based
Particle based
Sheet based
69
What are the fibre based composite materials ?
Carbon fibre reinforced plastic (CFRP)
Glass fibre reinforced plastic (GRP)
Fibre concrete
70
What are the particle based composite materials?
Tungsten carbide
Concrete
71
What are the sheet-based composite materials ?
Aluminium composite board
Engineered wood e.g. glulam
72
What is a smart material?
A material whose physical properties change in response to an input or change in the environment, which as electricity, pressure, temperature or light.
73
What are some examples of smart materials?
Shape memory alloys (SMA)
Thermochromatic pigment
Phosphorescent pigment
74
What is a modern material?
A material developed through the invention of new or improved processes, e.g. as a result of man-made materials or human invention.
Modern materials are not smart materials because they do not react to external change.
75
What are some examples of modern materials ?
Kevlar
Precious metal clay
High density modelling foam
Polymorph
76
What are the 2 types of test you can perform on a material to test its properties?
Simple workshops test (comparative)
Scientific measures test (industrial)
77
How can you do tensile testing? Using a practical workshop test
This can be tested in a workshop by clamping material samples of the same length and thickness into a vice and applying a load such as weight to the unclamped end.
This method can be used to see how much the material deflects under the load and/or how much load each material can beat with the least deflection. The less deflection under the load, the more tensile strength the material has.
78
How can you do toughness testing ? Using a practical workshop test
This test establishes how much impact force the material can absorb.
Materials are clamped into a vice. Each sample is the hit with the same force, using a hammer.
Tough materials will absorb the impact, where brittle materials may bend or even shatter.
79
What are the 2 aspects to testing hardness? Using practical workshop tests
Abrasive wear
Resistance to surface indentation
80
How can abrasive wear be tested on materials ? Using practical workshop tests
By running a file over the surface of the material, using the same force for each material surface.
The material with the fewest scratches is the hardest.
81
How can resistance to surface indentation be tested ? Using practical workshop tests
Using a dot pitch and a hammer. The material sample is fully supported underneath and the dot punch is placed onto the material surface. The dot punch is hit once with a hammer, using the same force for each material sample. The smaller the ident, the harder the material.
82
How do you test for malleability and ductility? Using practical workshop tests
Secure the test pice in a vice. Try to bend the test piece to 90 degrees. Cracks or surface damage on the outside of the end indicates a lack of ductility.
Cracks or surface damage on the inside of the end indicates a lack of malleability.
83
How can you test the rate of corrosion of a material when exposed to environmental effects such as rain or sun? Using practical workshop tests
All test pieces should be the same size. Materials can simply be placed outside in an area exposed to weather effects and left for a certain length of time. Materials can then be visually inspected for surface corrosion. Depending on the intended product function, further material testing such as toughness or hardness could then be carried out.
84
What are the 2 types of conductivity testing ?
Electrical conductivity
Thermal conductivity
85
How do you test for electrical conductivity in a material? Using practical workshop tests
Using a multimeter.
Collect samples of the same dimensions and, on the top surface, make a set distance between the 2 ends of the material sample. The distance is the spacing for each probe of the multimeter. Place the probes on the distance marks and measure the resistance on the multimeter. The high the resistance, the lower the conductivity.
86
How do you test the thermal conductivity of a material? Using practical workshop tests
Using a thermometer.
Collect material samples of the same dimensions. Measure a set distance from one end of the material on which to place a thermometer. A Bunsen burner is lit under the end of the material. Record the time it takes for the temperature to reach the set point at the other end of the material sample.
The shorter the time it takes to reach the set temperature, the higher the thermal conductivity of the material.
87
Using industrial testing, how do you test the tensile strength of a material?
A standard test piece is placed onto a tensometer machine and held in clamps at each end. One clamp is fixed and the other movies in a worm drive gear mechanism. As the worm drive travels at a constant rate, the test piece is put under tension. As the test piece is stretched, the load and distance is plotted, giving information on elastic limit, yield point, maximum load and final breaking point after ‘necking’.
88
Using industrial testing, how do you test the toughness of a material?
The Izod impact test is used to test the toughness. A notched test piece is held vertically in the vice of the test machine. A pendulum is realised from a set position and swings to strike the test piece. The energy absorbed by the test piece is calculated from the height of the pendulum swings to after it hits the test piece. The material that absorbs the most impact is the toughest. This is shown by the distance the pendulum swings after breaking the material. The further it swings, the less energy the sample absorbs and the more brittle the material.
89
Using industrial testing, what are the three common tests for hardness?
Rockwell
Brined
Vickers pyramid
90
What is the Rockwell test for hardness?
A preloaded is applied to the material sample using a diamond indenter, which breaks through just the surface of the material. The preload is the datum or zero reference position. An additional load is then applied to the test material and held for a predetermined length of time. The load is then released and the distance between the preload and applied load is measured, and the hardness is the material is calculated. The smaller the indentation depth, the harder the material.
91
What is the Brinell test for hardness?
A hardened standard size steel ball is forced into the materials surface using a pre-set load. The diameter of the indent in the surface is measured. The smaller the diameter indent, the harder the material.
92
What is the Vickers pyramid test for hardness?
Used for very hard materials, this test uses a diamond square-based pyramid to indent the surface of the material. Diamond is used because it well not deform under load. A microscope is used to measure the size of the indent. The smaller the indent, the harder the material.
93
Using industrial testing, how can you test the ductility and malleability of a material?
A bend test is used to determine how well a material can withstand cracking during one continuous bend. A ductile material will have a lot of plastic deformation prior to failure.
The test piece is placed into a bending machine and held, supported at the ends. A mandrel or plunger loads the test piece at the centre and bends it to a predetermined angle, or until the test piece fractures. The material is then inspected for cracks or defects. Cracks on the outer bend indicate the level of ductility. Cracks on the inside of the bend indicate the level of malleability.
94
What does NDT stand for?
Non-destructive testing
95
What is non-destructive testing ?
It is usually carried out on products such as large casting where there is a likelihood of an internal defect or imperfection which would not be detected by other methods.
96
What are the 2 standard NDT methods?
Ultrasonic
X-ray
97
What is ultrasonic testing ?
A transducer generates sound aces which are pulsed into the material. The intensity of the reflected sound waves signal is recorded on a display unit. The sound waves travel through the material and if there are any defects such as cracks in the sound waves’ path, the sound energy will be partially reflected and shown on the display unit.
98
When is ultrasonic testing used?
Can be performed in all types of materials.
It can be portable and has a high accuracy of flaw detection.
It is widely used in the offshore and aerospace industries and is commonly used to check the quality of welds in pipes for offshore oil applications.
99
What is X-ray testing ?
An x-ray beam passes through the material and an image is projected onto a display screen. X-rays allow the observation of tiny details within the material. The magnified images able minute flaws such as voids or hairline cracks to be reliably detected.
100
When can X-ray testing be used?
To inspect integrated circuits and printed circuit boards and to check for micro-voids in composite materials such as F1 cars.
It can also be used to detect faults in turbine blades or aeroplane engine blocks.
101
How can non-destructive testing be used to test electrical conductivity in industry?
A four-point probe method can be used to determine the electrical conductivity of materials. Four small-diameter wires are stretched, parallel to each other across a non-conductive polymer block, held in place and connect to copper terminal blocks. Two leads are attached to the inner wires and two to the outer wire a the outer leads are connected to a precise current and the two inner leads measure the voltage drop. Ohm’s law can then be used to calculate the resistance of the material sample.
102
How can non-destructive testing be used to test thermal conductivity of a material in industry ?
Using a heat flow meter, a square-shaped material test piece is placed between two temperature controlled plates. The temperature is increased at a controlled rate and the heat flow through the material is measured by the heat flow sensors placed on the surface of the material. As the material is heated to a specific temperature, the sensors measure and record the rate of thermal conductivity.
