Lecture 8 - Copper Alloys Flashcards
Which elements have higher conductivity than copper?
Silver
What reduces the electrical conductivity?
defects
alloys
What 5 things do defects include?
vacancies
impurities
dislocations
grain boundaries
twins
What are the four unique qualities of pure copper?
high electrical conductivity
high thermal conductivity
excellent ductility and toughness
good corrosion resistance
What happens when copper oxidizes?
degrades conductivity (P and B are added to deoxidize)
What happens when Al is added to Cu?
high strength fine dispersion of Al2O3
What are the four biggest reasons to use copper?
electrical conductivity
corrosion resistance
heat transfer
structural capability
What is brass?
5-40% Zn
What is Nickel Silver?
25% Zn + 10-20% Ni
What is Bronze?
4-12% Sn
What is Phosphor Bronze?
normal bronze + 0.2% P
What is Aluminum Bronze?
normal bronze + 3-10% Al, Fe, Ni, Sn
What is copper-nickel?
10-70% nickel
What is copper beryllium?
1-2.5% Be
Where does the strength of most Cu alloys come from?
solid-solution strengthening
cold working