Microstructural behavior of Copper Alloys
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Transcript of Microstructural behavior of Copper Alloys
Microstructural Microstructural behavior of Copper behavior of Copper AlloysAlloysEngr 45 Fall-05Engr 45 Fall-05By: Marco RuizBy: Marco Ruiz Justin MatariJustin Matari Jeremy RomanoJeremy Romano
What we did…What we did…
We casted several different combinations We casted several different combinations of copper alloys. of copper alloys.
Our objective is to observe how different Our objective is to observe how different microstructures can effect these alloys.microstructures can effect these alloys.
Like Dissolves LikeLike Dissolves Like
To obtain a fully dissolved solid solution To obtain a fully dissolved solid solution there needs to be some sort of there needs to be some sort of compatible relationship between a solute compatible relationship between a solute and a solvent.and a solvent.
Knowing the structural similarities Knowing the structural similarities between the two elements we are able to between the two elements we are able to predict whether one will dissolve into the predict whether one will dissolve into the other. other.
http://www.newton.dep.anl.gov/askasci/chem03/chem03348.htmhttp://www.newton.dep.anl.gov/askasci/chem03/chem03348.htm
Question?Question?
What happens when you attempt to What happens when you attempt to dissolve two different microstructures?dissolve two different microstructures?
This experiment will demonstrate the This experiment will demonstrate the behaviors of common alloys:behaviors of common alloys: brass, bronze, copper-silver. brass, bronze, copper-silver.
WarningWarning
Metal gets hotMetal gets hot Use appropriate Use appropriate
protectionprotection Well ventilated areaWell ventilated area
CastingCasting
Attempted to cast Attempted to cast alloys into a pure alloys into a pure calcium mold.calcium mold.
FailedFailed
Casting (back up plan)Casting (back up plan)
Alloy combinationsAlloy combinations
Sample
1Sample
2Sample
3Sample
4Sample
5Sample
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%Cu 100 85 60 85 60 85 7.5
%Ag - 15 40 - - - 92.5
%Zn - - - 15 40 - -
%Sn - - - - - 15 -
Hard Rh 43 Rh 66 Rh 71 Rb 44 * * Rh 55
Zero to low alloyZero to low alloy
Copper 925 silverCopper 925 silver Rh 43 Rh 55 Rh 43 Rh 55
Even distribution of grains Even distribution of grains
High Alloy (fcc structure)High Alloy (fcc structure)
60 Cu-Ag 40 85 Cu-Ag 1560 Cu-Ag 40 85 Cu-Ag 15 Rh 71 Rh 66Rh 71 Rh 66
Both are completely soluble no matter what %.Both are completely soluble no matter what %.
Ag-Cu Phase diagramAg-Cu Phase diagram
Sn (fct), Zn (hcp)Sn (fct), Zn (hcp)
85 Cu-Sn 15 85 Cu-Zn 15 85 Cu-Sn 15 85 Cu-Zn 15 Rb ? Rb 44Rb ? Rb 44
Grains act as barricades, non-uniform dist. Grains act as barricades, non-uniform dist. What a difference!!!What a difference!!!
Sn-Cu Phase diagramSn-Cu Phase diagram
Zn-Cu Phase diagramZn-Cu Phase diagram
60 Cu-Sn 4060 Cu-Sn 40
Solubility limit has Solubility limit has been reachedbeen reached
Unlike Unlike microstructuresmicrostructures
Extremely brittleExtremely brittle
60 Cu-Zn 4060 Cu-Zn 40
Not annealedNot annealed Extremely hardExtremely hard Solubility limit has Solubility limit has
not been reachednot been reached
DiscussionDiscussion
Like solvents, not all molten metals are fully Like solvents, not all molten metals are fully miscible with each other.miscible with each other.
http://www.meta-synthesis.com/webbook/38_laing/tetrahedra.htmlhttp://www.meta-synthesis.com/webbook/38_laing/tetrahedra.html
Copper and zinc ions are about the same size, so except for the electric charge, they are pretty much the same so far as the crystal is concerned……
http://du.edu/~jcalvert/phys/zinc.htmhttp://du.edu/~jcalvert/phys/zinc.htm
Copper ions harden silver by the size of the Copper ions harden silver by the size of the atom. Smaller copper ions cause interstituals in atom. Smaller copper ions cause interstituals in the silver. But, they do not harden copper nearly the silver. But, they do not harden copper nearly as much as tin or zinc.as much as tin or zinc.