Unit 2-E Flashcards
What are the tests for material toughness (destructive)?
Izod test or Charpy test
‘Notched’ material sample and a pendulum are used
What are the 3 tests for material hardness (destructive)?
Vickers pyramid test
Rockwell test
Brinell test
How does the Vickers pyramid test work?
Triangular pyramid is pressed into material
hardness from force and size of depression
How does the Rockwell test work?
Measures the indentation of a large weight and a small weight
How does the Brinell test work?
Sphere is pressed into material
Hardness is found from force and size of depression
What are the tests for material tensile strength (destructive)?
Uses a tensometer
They are clamped at either end
One clamp moves away from the other
Plastic limit, yield and breaking point can be recorded
What is the test for thermal conductivity?
The rate at which heat moves through a material can be measured using thermometers or heat flow meters.
What is the test for electrical conductivity?
The rate at which heat travels through a material can show how good a material is at conducting electricity
What is a test for ductility?
Sample attached to a fixed and rotating vice
Number of turns and type of break indicate ductility properties
What is a test for malleability and ductility?
Sample clamped in vice
Bend 90 degrees
Cracks or damage on outside = lack of ductility
Cracks or damage on inside = lack of malleability
What is a test for elasticity?
Sample fixed between moving and static vice
Moving vice moves increasing distance side to side
Movement is increased until the material does not return to its original position
What are some methods of carrying out qualitative tests?
Interviews
Questionnaires
Surveys
Focus groups
User observations
What can designers use to help select materials?
Tables comparing values:
Strength VS toughness
Density VS tensile strength
Cost VS strength
Stiffness VS strength
What materials are commonly cold worked?
Low carbon steel
Copper and its alloys
Stainless steel
Aluminium alloys
What are the benefits of cold working?
Increases strength, hardness and wear resistance due to permanent defects in structure
Better surface finish and dimensional accuracy
What is resistance to abrasion and what are the positives?
Withstands wear caused by friction or rubbing
Increases the lifespan
What materials are suitable for embossing?
Glass
Metal
Fabric
Paper
Plastic
