Aum's Deck

Question 1

What are the 4 benchmark Hardness tests and 3 portability tests?

Answer 1

4 benchmarks: “Brinell test”, “Rockwell tests”, “Vickers tests”, and “Knoop tests”.
3 portability: “Sceleroscope or Shore tests”, “Leeb hardness”, “Durometer hardness”

Question 2

what are the Brinell, Rockwell, Vickers, and Knoop tests?

Answer 2

Brinell: Use a hardened steel or tungsten carbide ball to produce indentation. Produces accurate repeatable results on materials such as castings and forgings.
Rockwell: Measures the depth of impression from a specific indentor. It is fast and used on materials such as metals, alloys, small precision parts, wire and even plastics.
Vickers: Uses variable loads and diamond pyramid indentor. It is used on small precision parts, thin materials, wires and coatings.
Knoop: Explores microhardness by making rhombohedral indentations with a pyramidal diamond indentor.

Question 3

What are the Sceleroscope/Shore, Leeb and Durometer tests?

Answer 3

Sceleroscope/Shore: Is a rebound test that measures losses in kinetic energy from a falling diamond-tipped metal ‘tup’. It has become obsolete due to the Leeb test.
Leeb: Is a rebound test used for on-site testing. the change in velocity of a spring-loaded device impact body within a pen-shaped device is measured electronically. The velocity is proportional to the voltage induced in the device.
Durometer: Is principally undertaken on polymers and involves pressing an indenter into a test piece.

Question 4

Where are hardness tests used in vehicle components?

Answer 4

-Engine crankshafts, cams and camshafts, Tyres, lacquers and coatings, vehicle interiors and plastic components.

Question 5

What are the 2 impact tests?

Answer 5

Charpy impact test
Izod impact test

Question 6

What is the Charpy test?

Answer 6

a high strain-rate test that involves striking a standard notched specimen with a controlled weight pendulum swung from a set height.

Question 7

What is the Izod Test?

Answer 7

a pendulum will hit the specimen and the pendulum’s potential energy is determined according to the mass and the drop height.

Question 8

What is the difference between charpy and izod testing?

Answer 8

The Izod impact testing holds the sample vertically with the notch facing the pendulum. The Charpy impact testing holds the sample horizontally with the notch facing away from the pendulum

Question 9

What are some control technologies that monitor operations?

Answer 9

-Fuel gauge
-Engine oil pressure
-Coolant temperature
-Fuel injection

Question 10

What are some control technologies that control various functions?

Answer 10

Speed-Cruise control
braking-ABS system
Vehicle grip-Traction control
Gear changes-automatic transmission
Air bags-deployment with rapid braking
Headlights-automatic off with key out of ignition

Question 11

What is a polymer?

Answer 11

A polymer is a large organic compound, they may be natural or synthetic and share the common feature of being on a carbon chain.

Question 12

What are some examples of natural polymers?

Answer 12

1. Silk
2. Wool
3. Cotton
4. Starch
5. Cellulose
6. Rubber

Question 13

what are some examples of synthetic polymers?

Answer 13

1. Polyethylene
2. Nylon
3. Neoprene
4. Teflon

Question 14

What are the 2 categories of polymers?

Answer 14

1. Thermosetting
2. Thermosoftening

Question 15

What is the molecular bonding like in thermosetting polymers?

Answer 15

The bond (covalent) between molecular chains are very strong and thus resist melting.

Question 16

What are some mechanical properties of thermosetting polymers?

Answer 16

1. Flame resistance
2. Optical properties
3. Impact toughness
4. Chemical resistance
5. Strength and stiffness
6. Environmental durability
7. High thermal and mechanical properties

Question 17

Uses of thermosetting polymers in aircraft?

Answer 17

Canopies, windscreens, windows, structural members, tyres, coatings, wall sections and interior linings.\

Question 18

Suitable methods for forming thermosetting plastics:

Answer 18

1. Injection molding
2. Transfer molding
3. Compression molding

Question 19

What is compression molding?

Answer 19

Is a manufacturing process where a measured amount of molding material that’s generally preheated (typically referred to as a charge) is compressed into the desired form using two heated molds.

Question 20

What is Hand lay-up?

Answer 20

It is the simplest method for open molding composite material. it is used for low-volume production or large complex components. It is used when product thickness tolerances are less critical.

Question 21

What is vacuum lay-up?

Answer 21

This technique is an extension of the hand lay-up process where the pressure is applied to the laminate once it has been laid up in order to improve its consolidation.

Question 22

Modifying materials for aircraft applications:

Answer 22

The use of naturally occurring materials such as wood, metal, and natural-fibre fabrics has all but disappeared from the aviation industry. Today highly modified materials, synthetics, and advanced composites dominate the materials of choice for aircraft construction

Question 23

What are the changes in the macro- and microstructure of Nickel?

Answer 23

Macrostructure: Nickel typically has a silver-white color with a shiny metallic luster. It is a ductile metal that can be easily drawn into wires or flattened into sheets. The macrostructure of nickel remains relatively unchanged under normal conditions.
Microstructure: Nickel has a face-centered cubic (FCC) crystal structure. At the microstructural level, changes can occur due to various factors such as alloying, heat treatment, and mechanical deformation. These changes may result in the formation of grain boundaries, precipitation of secondary phases, and dislocation structures.

Question 24

What are the changes in the macro- and microstructure of Copper?

Answer 24

Macrostructure: Copper has a characteristic reddish-brown color and is highly ductile. It is commonly used in electrical wiring and plumbing due to its excellent conductivity. The macrostructure of copper remains relatively stable.
Microstructure: Copper also possesses an FCC crystal structure. Microstructural changes in copper can occur due to alloying, heat treatment, or mechanical deformation. These changes can lead to the formation of grain boundaries, the precipitation of secondary phases, and the presence of dislocations, which affect its mechanical and electrical properties.

Question 25

What are the changes in the macro- and microstructure of Magnesium?

Answer 25

Macrostructure: Magnesium is a lightweight metal with a silvery-white color. It is known for its high strength-to-weight ratio and is widely used in various industries, including aerospace and automotive. The macrostructure of magnesium typically remains unchanged.
Microstructure: Magnesium has a hexagonal close-packed (HCP) crystal structure. At the microstructural level, changes can occur due to alloying, heat treatment, and mechanical deformation. These changes may lead to the formation of grain boundaries, precipitates, and dislocations, affecting the mechanical properties of magnesium alloys.

Question 26

What are the changes in the macro- and microstructure of Aluminium?

Answer 26

Macrostructure: Aluminum is a silver-white metal known for its low density and high corrosion resistance. It is extensively used in various applications, including construction, transportation, and packaging. The macrostructure of aluminum remains relatively stable.
Microstructure: Aluminum also has an FCC crystal structure. Microstructural changes in aluminum can occur due to alloying, heat treatment, or mechanical deformation. These changes may result in the formation of grain boundaries, precipitation of alloying elements, and dislocation structures, influencing the mechanical properties and formability of aluminum alloys.