Metal Deformation: Fatigue, Hardness & Creep Flashcards
What is metal fatigue?
Metal fatigue is failure due to on/off loading or cyclic stressing.
What does metal fatigue begin as?
It begins as a small crack which grows under action of fluctuating stress.
What is metal hardness?
Hardness is the property of the material which enables it to resist plastic deformation, usually penetration or by indentation.
What is hardness also referred to as?
It is also referred to as temper or the resistance to bending, scratching or abrasion.
What is metal creep?
Creep is the slow deformation of a material over time resulting from a constant force acting on the material.
What does metal creep occur as a result of?
Metal creep occurs as a result of long term exposure to high levels of stress that are below the yield strength of the material. Temperature and time are contributing factors.
Identify factors that influence creep
Creep happens faster at higher temperatures.
An example is a length of lead hung on the wall stretching because of gravity pulling it down.
identify ways to prevent corrosion
Galvanising (iron or steel with zinc)
Dip coating
Cathodic protection
Barrier coatings
