6.1 Ferrous Metals And Intro Flashcards
Why is aluminium preferred in aircraft construction over steel
Because aluminium is less dense
When an aircraft is subject to cyclic loading it will begin to crack, what is this known as
Fatigue
What is stress defined as
Force per unit area
Hardness
Resist penetration, wear or cutting action
Material strength
Resists deformation
Toughness
Resist being deformed with out braking
What is yield strength (2)
The maximum amount of stress applied to a material with out permanent deformation
What is ultimate tensile strength
The maximum load a material can take with out breaking
When selecting metals for aircraft structure what sort of density can the metals have
Under 5 kg/dm cubed
What crystal structure does iron have above and below 910°c
BCC below 910° and FCC above 910°c
What should material selection be a compromise between
The quality of the material to for fill its roll and all costs
What are the 2 major setbacks of steel
High density and high susceptibility to corrosion
What are the pros and cons of alloying sulphur to steel
The pros are improved machinability the cons are Reduction in weldability and ductility with increase in use
What characteristics does manganese contribute when alloyed to steel
Strength and hardness but less so than carbon
What is the purpose of silicon when alloyed with steel
A de oxidiser, has a bad effect on surface finish
