CSA metals and alloys Flashcards
What is metallic bonding ?
positively charged metal ions held in sea of delocalized electrons
o So conducts electricity
What is the grain boundary in metals ?
• small space in between the grains is disordered
What happens when metal moves from liquid to solid phase?
vibrations of ions decrease so energy released to surroundings
How to form a metal solid from liquid?
small undercool is needed
When is metal both liquid and solid at the same temp. in equilibrium ?
freezing or melting point of metal
What is an alloy?
mix of more than one metal in solid state
Why are alloys used over pure metals?
alloys tailored to suit need considering strength, modulus, corrosion resistance .
What are binary alloys?
focus on mixture of two metals as an alloy
What does a cooling curve of an alloy indicate >?
alloy doesn’t have a melting point, but a melting range
What is lower line on cooling curve of alloy?
solidus
What is upper line on cooling curve of alloy?
liquidus
