IET FINAL EXAM Flashcards
List 3 Main Classes of Manufacturing
-Joining
-facing
-shaping
When a metal fractures beyond the yield point, it is said to be
Ductile
For all practical purposes is a rubber band is brittle or ductile material
brittle
Possion’s Ratio to steels
v = 1/3
Possion’s Ratio to Elastomers
v = 1/2
Which of the following drives the material selection for a given product?
Design/Performance
Why do we use a stress strain diagram
- True stress strain diagrams do not give a UTS
- Engineering Stress strain diagrams are easier to measure
To determine how to read any analog instrument, one must be given
Greatest number on the measuring tool
What type of bonds allow the long chains in to “Slide” over each other? This bonding type allows elastomers to be very stretchy.
Covalent Bond
Cannot reheat and have many cross links
thermosets
Can reheat and do not have as many cross links
thermoplastics
Common thermoplastics
-Poly Ethelyne
-Polypropylene
-Polystyrene
-Polyvinyl Chloride
Plastics Vs Metals
-coefficient of thermal expansions is higher for plastics
-Plastics are difficult to repair
What is toughness
combo of yield strength and how much you plastically deform it
Largest use of plastics
packaging