For questions about alloys.
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41 views
Why doesn't rose gold tarnish?
I was looking into rose gold, and I was wondering how long it takes for the alloy to tarnish. The results I got from a couple sites state it doesn't. One of them said, however, it develops this patina....
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0answers
38 views
Find alloy composition by density
I have a square piece of metal from a processor heat sink that looks a lot like copper. I'm trying to find the alloy composition but I'm not sure how.
I happen to have both a digital caliper and a ...
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1answer
99 views
Which karat gold is harder, 24 kt or 18 kt?
$\pu{24 kt}$ gold indicates that $24/24$ part of it, i.e. $100\%$ of it is gold. $\pu{18 kt}$ indicates that $18/24$ part of it is gold. As gold is a soft element, I reckoned that $\pu{18 kt}$ gold ...
6
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0answers
74 views
What are metal zip tags and belt buckles made of?
Metal zipper tags and belt buckles melt very easily and can be melted by heating it in the stove for 5 minutes. But other metals like aluminium refuse to melt even after hours.
If you leave it ...
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2answers
100 views
Boric Acid and Brass Alloy
Can someone explain why boric acid prevents zinc from vapourizing out of the brass alloy when it is being melted? What is the actual chemistry occurring and why?
Thanks
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1answer
48 views
How does bismuth's lone pair affect its properties as a metal and alloy?
Bismuth is really the only metal to exhibit a lone pair in its outermost shell, this means that it and its salts should be a Lewis base. As bismuth can act as a Lewis base, how does this affect its ...
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38 views
What is Latinum an alloy of?
I was looking at grad rings from my university and one of the material options is Latinum. Anyone know what this is an alloy of?
Any time the term is included in a search, it brings up a bunch of ...
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0answers
15 views
If a reactor made up of alloy has ceramic coating inside, can the temperature inside be raised to 500C?
I would like to get a reactor fabricated for plastic pyrolysis. The temperature would maintained around 520C. The material processed would be Waste Polypropylene and Polyethylene.
With the ceramic ...
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1answer
31 views
How would ceramic coating inside the reactor affect heat transfer? [closed]
With the ceramic coating, would I be able to get its internal temperature raise upto 520.
I would like to get a reactor fabricated for plastic pyrolysis. The temperature would maintained around 520C. ...
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0answers
16 views
What is the reason behind the 2% decrease in silver metal composition just after melting the raw silver alloy (55% silver)? [duplicate]
I determined the silver composition from an alloy obtained from a jeweler to be 57% and wanted to extract silver out of it. However, upon melting around 5 kgs of alloy, the silver composition went ...
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1answer
48 views
What is the reason behind the 2% increase in silver metal composition just after melting the raw silver alloy (55% silver)? [closed]
I determined the silver composition from an alloy obtained from a jeweler to be 55% and wanted to extract silver out of it. However, upon melting around 5 kgs of alloy, the silver composition went up ...
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2answers
177 views
Brass Instrument: Dezincification or just scrubbed off?
I do own a brass instrument (a trombone). The lacquer is damaged.
I asked how to deal with it here.
Now I learned that the brass contains zinc, and there is a corrosion process called "...
3
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1answer
37 views
Which is the suitable process for ball milling?
Why do we mainly choose the wet ball milling process in spite of dry ball milling process? Both processes are used to make a homogeneous mixture of different compounds.
2
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0answers
44 views
Structural entity for the tattoo resembling spine surgery involving 6AL-4V ELI alloy
I have very little background in chemistry, so forgive me if I sound ridiculous and uneducated.
I want to have a tattoo designed in honor if my spine surgery that I had. I think that molecular ...
4
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1answer
68 views
Why did my milled powders catch fire?
I milled a small amount of the sample ($75\%$ Al, $15\%$ Cu, $10\%$ Ni) mixed with toluene for 5 hours after which I set it on butter paper to dry. Then after 13 minutes I switched on the fan in the ...
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0answers
38 views
Iron-platinum refining
If I have an iron-platinum alloy, can I put this into a solution of $\ce{HCl}$ to dissolve the iron, leaving a $\ce{Pt}$ precipitate?
I know that Fe dissolves in $\ce{HCl}$ to form $\ce{FeCl2}$ and $\...
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1answer
1k views
Does cold bluing steel prevent rust?
I've recently purchased a Damascus knife and am patiently awaiting it's arrival in the mail. I have been researching the potential care and maintenance habits for this craftsman blade, hoping to keep ...
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2answers
1k views
What does “René” mean in René alloys?
René alloys are nickel-based super alloys (René 41, René 88, René N5 etc. etc.). But how did it get the name René? Is it an acronym or contraction of other terms? It was created by Earl Ross and the ...
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2answers
735 views
How do foundries prevent zinc from boiling away when alloyed with Aluminum?
How do foundries prevent lower boiling point metals such as zinc from boiling away when alloyed in a furnace with higher boiling point metals such as aluminum?
5
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1answer
77 views
Why don't alloys self-galvanically corrode?
Total chemistry newbie here (so this may be a fairly obvious question). With that said, I've had a niggling question that I can't quite resolve myself;
Given that galvanic corrosion is driven by the ...
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1answer
66 views
Are there non-brittle silicon-based alloys? [closed]
Requirements:
Silicon part is greater than 50%
Has plasticity comparable to iron.
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0answers
279 views
Unexpected color of nickel oxide; contamination?
I synthesized Nickel(II)Oxide from Nickel(II)Carbonate and instead of the green color that I was expecting, I got a brown powder.
After searching a bit I found that this could be due to Cobalt ...
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1answer
157 views
Why are there two vertical axes in the iron-carbon diagram? [closed]
More precisely, why do we have two axes that represent the same parameter, which is temperature?
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0answers
111 views
Very fast brass oxidation
I work for a company that manufactures pyrotechnics for the oil and gas industry, and we have been having an odd phenomenon occur.
One part, a brass tube with a copper clip filled with black powder, ...
2
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1answer
243 views
How can I find the eutectic point of gallium and aluminum?
I've been interested in liquid metals for a while, but I've stayed away from mercury for obvious health reasons. I have a sample of gallium and I've seen a liquid metal mixture of gallium and aluminum....
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0answers
633 views
Density of Interstitial compounds
I have read in my textbook (not very reliable) that density of interstitial compounds is lesser than parent compound. But how can this be true?
We add atoms to the lattice voids, so density should ...
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1answer
32 views
Cell walls in lath martensite - Meaning
What does cell walls mean in the context of lath martensite? Are they grain boundaries?
Quote (page 66 Structure and properties of engineering alloys - Smith): In the lath martensite of low-carbon ...
14
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1answer
770 views
Can a small amount of scandium be added to gold, platinum or palladium to create a wedding ring?
The number 21 has a special meaning to us, so we would like to make wedding rings with some scandium in it (element 21). I know scandium can be alloyed with aluminium or titanium, but can it also be ...
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1answer
320 views
Measuring lead content in pewter
I've bought pewter at the thrift store and I want to try casting metal. This pewter may contain toxic metals. A ready-made testing kit I've found cost €25 for each sample.
In comparison pewter of ...
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1answer
150 views
Reasons for existence of eutectic point for alloy systems
Why does a eutectic point exist for a system of alloy ? Why is it that there is such a definite ratio of composition at which this occurs ?
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1answer
5k views
How to separate alloys?
How do you separate metal alloys into their constituent elements, especially industrially? I don't think you can always use melting points, because alloys, depending on the composition (looking at ...
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1answer
122 views
Composites of Immiscible Solids - Aluminum and Lead Example
The $\ce{Al}$-$\ce{Pb}$ (aluminium-lead) phase diagram clearly depicts that when cooled from the liquid state, aluminium and lead are not miscible in the solid state, i.e. the crystal structure of ...
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1answer
94 views
How soluble is uranium in molten iron?
As I know, uranium and iron simply aren't mixable, which means there are no U-Fe alloys. The Google says, uranium is insoluble in molten iron.
But, if something is "insoluble", it actually means only ...
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0answers
306 views
Why does Devarda's alloy include copper?
Devarda's alloy is used in the detection of nitrates. However, judging by the reaction equation, only aluminium plays the role of reducer:
$$\ce{3NaNO3 + 8Al + 5NaOH + 18H2O -> 8Na[Al(OH)4] + 3NH3(...
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0answers
5k views
Difference in properties between a substitutional and an interstitial alloy? [closed]
What I know is, that in a substitutional alloy, the atoms of the solute metal take positions normally occupied by the solvent metal atoms, as they are more or less the same size. In an interstitial ...
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0answers
47 views
If I have an alloy of two materials, will I have a chemical reaction between the two materials
I have always been told that an alloy is a mixture without chemical interference between the materials, but if I look at highly doped silicon (doped with Aluminum via ion implantation and then lattice ...
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1answer
280 views
To extend the life of a cartridge razor blade, should the blade be stored in oil or alcohol?
I've read varied recommendations about extending the life of a razor blade. Some say should stick the blade in oil when not in use, others say in alcohol, others say in a bowl of rice or silica gel.
...
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1answer
127 views
Identify what alloy of metal tool
The title is more general than my particular question, in particular I bought a "allen key" and it broke after doing a lot of force with it trying to turn a hard screw.
In order to get a harder tool I ...
3
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0answers
57 views
Is it possible, given a target temperature, to create an alloy that melts at precisely that temperature?
Assuming the target melting points are between the melting points of mercury and tungsten, is it possible, given a target temperature, to create an alloy (or compound) composition that has a direct (...
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1answer
72 views
Product of lead and tin alloying
It is common knowledge that tin melts at $449.5~\rm^{\circ}F$ and Lead at $621.5\rm~^\circ F$, and that when these are melted together you simply have an alloy.
What happens, or what product occurs, ...
6
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1answer
925 views
Why doesn't my stainless steel Thermos get really really hot?
Why doesn't my stainless steel Thermos get really really hot? Seems like a fairly straightforward question.
A few notes:
I was looking and found (obviously different values because steel is an alloy)...
7
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2answers
735 views
Miscibility of Molten Metals
While reading about the size of atoms and ions of the Group 1 elements in the textbook "Concise Inorganic Chemistry" by JD Lee, I came across this line:
The Li+ is much smaller than the other ions. ...
2
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1answer
141 views
Alloys/metallurgy : promising elements for for Sn-based solders
I am trying to research potential modifications to lead-free solders (intended to be used in electronics). Base alloy is eutectic $\ce{Bi_{58}Sn_{42}}$, and I am going to add various combinations of a ...
2
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0answers
58 views
Generating Precipitation Diagrams with CompuTherm Pandat
I am trying to develop precipitation diagrams for an Ag-Cu-Sn alloy to figure out the kinetics involved using the CompuTherm Pandat Software (Demo Version).
The precipitation diagrams need the ...
7
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1answer
343 views
Ag-Sn-Cu Phase diagram to formulate homogenization temperature / duration
I am working on Ag-Sn-Cu alloy phase diagram to figure out the best temperature / duration to homogenize the alloy (annealing). The %age of elements in the alloy are
Ag - 40 %
Cu - 27.8%
Sn - 32.2 %
...
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2answers
2k views
Separating nickel coin into copper and nickel components
I'm trying to create a high school level lab in which we separate the metals in an alloy. The objective is to understand and apply standard reduction potentials, and also to do some extra redox ...
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2answers
2k views
If alloys are homogeneous mixtures, why can't we separate their components?
An alloy is a material composed of two or more metals or a metal and a nonmetal. And, they are usually formed by heating the elements to their melting points, and then cooling them, so that the ...
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1answer
118 views
Are there compounds that melt under their own weight?
Is there a compound that can melt under its own weight? That is, a block of such material remains solid when put horizontally but starts to melt when put vertically or remains solid in microgravity, ...
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0answers
239 views
Co49Ni21Ga30 - molar mass and density
I need to calculate the molar mass and density of the shape memory alloy $\ce{Co49Ni21Ga30}$
(I suppose the numbers indicate the mass percentage).
To get the molar mass, is it correct to use the ...
5
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2answers
6k views
Why does mercury not form amalgam with iron?
I am learning about solutions and while giving an example of a liquid (solute) and a solid (solvent), my teacher told us that mercury forms an amalgam with all the metals except iron.
I want to know ...
