Questions tagged [metallurgy]
Chemical and physical characteristics of metals and alloys.
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Is heat treatment the only way to increase grain size in steel?
Heat treatment is a well-established method for increasing grain size in steel. Is there any other approach known to man? I cannot seem to find anything via web search.
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If gold does not oxidise in air, why doesn't it reform it's lattice?
It is a common fact that without oxidation, a metal can reform it's lattice with a tad bit of pressure.
Gold is often said to be non-oxidising(doesn't oxidise in ambient temperature and pressure) and ...
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What are disadvantages of methane or ammonia compared to dihydrogen for metal ore reduction?
Metallurgy, such as steel-making processes, require reducing agents to get rid of the oxygen in metal ores. Using fossil coal for this is a large source of $\ce{CO2}$ globally. Recently, I have read a ...
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Why I am unable to see any electrical conductivity in Permalloy nano powders?
We recently purchased some permalloy nano powders (Ni80Fe70Mo3) I checked the electrical conductivity of these powders using a multimeter which can measure resistance to the order of giga ohm's. I was ...
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Malleability and Ductility Origins [closed]
Malleability and Ductility are both properties of metals. I have learnt that lead is malleable but not ductile. However, don't these properties both arise from metallic bonds? So how can a substance ...
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Does anybody know anything about this patented, late-19th-century process for producing white lead?
I debated on whether to put this question in the History or Engineering Stack Exchange. Ultimately, I decided on the Engineering Stack because I believe the people on this site will understand the ...
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Is it necessary criteria that we draw Ellingham diagram for only one mole of oxygen consumed for a given reaction
In my textbook and many other reference text shows Ellingham diagram for only one mole oxygen consumed. Why is this done?
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Are zinc & copper extracted from its ore using cyanide salt?
In my textbook, the extraction of Zinc is done from $\ce{ZnS}$ and copper from Cuprous oxide, so neither of extracting procedures involve the use of $\ce{CN^-}$ salts.
Thinking further, both Zn(II) ...
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Finding chromium
If I were to go back in time to pre-industrial Earth, and I wanted to make stainless steel, would there be a way to find chromium and/or chromite? It doesn't matter what chemical form the chromium ...
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Is electrode reduction potential dependent on the nature of the solution(the reagents of the solution) it's dipped in?
I'm undergrad student majoring in materials science and engineering. I faced this question while studying for a course named "surface engineering of materials".
This slide is a part of my ...
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Determine if particles are aluminium oxide
I am getting a white dust in my car, coming from the air vents and landing all over, mostly on the dashboard. After searching about this, it seems that it could be caused by the fins of the air ...
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How is decarburisation achieved during Electric Arc Furnace steelmaking?
In the basic oxygen process, steel is made from pig iron (having a high carbon content) by oxidising the carbon with a high-pressure oxygen lance.
In an EAF, steel is made mostly from scrap, but it ...
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Why does cold welding not work with carbon steels?
Cold welding is the process of joining metals using pristine surfaces without contaminents(oxide layers, oil, dust...) using pressure through atomic diffusion between the metal joints. Why does this ...
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Why does FCC crystalline forms form hexagonal crystalline structures during CVD?
During the CVD process, Copper and Nickel which are both Face Centered Cubic crystalline structures are used as substrates for shaping hexagonal atomic structures such as graphene and hexagonal Boron-...
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Why does the Gallium-Aluminum Reaction Happen? [duplicate]
There a plenty of videos online of a small gallium sample being placed on a large aluminum sample, resulting in the former being absorbed by the latter and forming an extremely brittle alloy. What I ...
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Can metals have both Fracture Toughness and Elasticity properties? [closed]
Fracture Toughness is the resistance of a material to cracking and Elasticity is the ability to bend without breaking. I want to know if there is any metal or metal alloy that can easily bend without ...
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Why is silver considered a "type 1" metal although it has multiple oxidation states? [closed]
I noticed that the metals I learned were "type 1" back in early chemistry class as they have one oxidation state including silver, aluminum, zinc, and cadmium. However, those metals weren't ...
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Separate aluminium from brass threaded bushing without affecting the brass
I wanted to separate aluminium from brass threaded bushing without affecting the brass.
I also suppose that brass isn't the brass but it's a phosphor bronze.
Does brass and phosphor bronze amalgamate ...
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Which gases(or gas) are evolved in the leaching of Galena(PbS) with conc. Nitric acid? [closed]
I want to know the gases produced(primarily nitrogen oxides) in leaching of Galena in nitric acid and the effect of concentration of nitric acid on the gases evolved.
I found papers about the ...
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Is anodizing of mixed metals (aluminium and cooper) possible?
I'd like to blacken my Noctua NH-P1 passive cooler, made from an aluminium fins and copper heatpipes. Since thermal dissipation is key in my build, I thought about anodizing it, instead of spray paint ...
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Calculating pourbaix diagram of Fe-H2O system at different temperatures
I have been trying to calculate the pourbaix diagram for Fe-H2O at different temperature for my high school research but I am facing a lot of problems. I have several question regarding the ...
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What is the reason for extracting copper from copper pyrites and not iron?
Why can copper be extracted from copper pyrites ($\ce{CuFeS2}$) but not iron? Is there some intuitive logic behind it?
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Gold cyanidation process
My chemistry book says the following:
In the metallurgy of silver and gold , the respective metal is leached with a dilute solution of $\ce{NaCN}$ in presence of $\ce{O2}$ as a result of which the ...
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Can a plain sheet of stainless steel adhering to the 316 grade be regarded as food safe at every finish level?
My question is not purely about chemistry but it definitely involves it.
I was looking for a while to buy a food-grade stainless steel plate that would fit my home pizza gas oven (to have the dough ...
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Ellingham diagram/graph for tungsten
I've recently come across one of the methods to form tungsten carbide($\ce{WC}$) from wolframite ($\ce{(Fe,Mn)WO4}$) by using carbothermic reduction which was supposedly one of the first methods for ...
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Aluminum Alloy with most alkaline resistance [closed]
Previously i asked this question in Engineering SE: What aluminum grade is the most resistant to corrosion in alkaline environment?
Some input from others seem indicating that no mass-produced ...
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How to determine the visual properties of a specific steel compound?
The material that is described in a paper by Li et. al.[1] is interesting to me, but they don't go into any details on what the end result would look like visually. Out of curiosity, I was wondering ...
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How to Improve Phosphoric Acid 85% leaching of Natural Titanium Rutile without increasing impurity?
Using magnetically separated natural titanium rutile from a mine in South Africa to leach titanium for oxide production using H3PO4 85%. (The reason for using H3PO4, is that it separates out any Fe ...
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Dehydrating hydrated Magnesium chloride
I came to know that hydrated Magnesium chloride $\ce{MgCl2.6H2O}$ is dehydrated not directly by heating as it gets hydrolysed to $\ce{MgO}$ . But instead it is dehydrated by passing through $\ce{HCl}$ ...
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The role of 2-nitrophenol in tin etchant (aqueous mixture of 2-nitrophenol and NaOH)
Aqueous mixture of 2-nitrophenol and NaOH is a time-honored etchant that dissolves tin-rich alloy and retain the intermetallic compounds from the tin. I wonder the role of 2-nitrophenol in the etching ...
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How can steel be so different from iron, even if amount of carbon is small?
Perhaps I am too naive, but I am having a hard time visualizing how even 'high-carbon' iron and steel alloys are maybe, at most, about four percent carbon by mass, which still means only one (smaller) ...
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Natural preservatives of ink
Would pure compounds like thymol, carvacrol, and cinnamaldehyde work as preservatives of fountain pen ink? I'm specifically interested in three properties -
Prevention of growth (mostly fungal) in ...
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Extraction of copper from chalcopyrite
During the extraction of copper from chalcopyrite ore, the ore ($\ce{Cu2S.Fe2S3}$) is heated to form $\ce{Cu2S}$ and $\ce{FeS}$. Then during smelting it reacts with $\ce{O2}$ to form $\ce{Cu2O}$.
Then ...
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Why do mineral particles become wet by oils while the gangue particles by water?
In my textbook, NCERT Chemistry for class 12, it is mentioned that one of the principle of froth floatation method is the following:
The mineral particles become wet by oils
while the gangue ...
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Why is the term "nascent nitrogen" still used in metallurgical industries?
Continuation of Why do nitrogen-containing organic compounds give N2 as the combustion product? (comment converted into question)
Nascent state is an obsolete theory in chemistry and is discredited. ...
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How to separate Cu and Ni from alloy containing different metals such as Al, Cu, Ni, (Zn, Pb, Sn < 5%)?
I have an alloy containing different metals such as Al, Cu, Ni, (Zn, Pb, Sn, Ag, Si in small amount < 5%). How can I separate Cu and Ni from this alloy?
I tried to dissolve alloy in sulfuric acid, ...
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Why is the only natural source of radium compounds uranium minerals?
A common mineral of barium is barytes, or barium sulfate ($\ce{BaSO4}$). Because elements in the same periodic group have similar chemical properties, we might expect to and some radium sulfate ($\...
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What is the alloying composition of the Zinc-Platinum System?
My research team and I are working on a bimetallic alloy consisting of Zinc and Platinum. We have looked for papers regarding the composition of Zinc-Platinum alloy. But there aren't many papers out ...
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Why same metal salt is required in electrolytic refining?
Why we use same metal salt in electrolytic refining?
Ex. For $\ce{Cu^2+}$ if we take suppose $\ce{FeSO4}$ so there are 2 ions ready to react on cathode ie $\ce{Fe^2+}$ and $\ce{Cu^2+}$.
But from a ...
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Why is the formation free energy of carbon dioxide almost constant in Ellingham diagrams?
While reading about Ellingham diagram in my textbook, I noticed that for:
$\ce{C_(_s_) + O2_(_g_) -> CO2_(_g_)}$,
the standard Gibbs free energy ($\ce{\Delta_fG^\circ}$) doesn't seem to vary with ...
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Why are calcination and roasting processes carried out at a temperature just below the ore's fusion temperature?
I had read about the two important methods used for the concentration of an ore - Roasting and Calcination. I have a doubt regarding why both the methods are carried out at temperatures not above the ...
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How thick is the colored oxide layer on heat treated stainless steel? [closed]
When stainless steel is welded, or just heat treated, it will develop a thicker oxide layer, which in some cases is is rainbow colored, but can become so thick as to appear almost black. From the ...
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Why does Cody use Litharge? [closed]
In many of the precious metal refining videos Cody (Cody's Lab) takes the sample with the precious metal and puts Litharge into it. After heating it in the furnace, while pouring it out the molten ...
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Why are rare earth metals and platinum group metals are often found clustered together in ores
Rare earth and platinum group metals are often found clustered together in the earth's crust. Mining for platinum, for instance, also yields Rhodium and Ruthenium belonging to the same group. Likewise,...
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Roasting of galena
In the metallurgy of $\ce{Pb}$, Galena is first concentrated by froth floatation process. It is then partially roasted to and self reduced to obtain $\ce{Pb}$.
Why is galena only partially roasted(...
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Calculating change in Gibbs Free Energy for a specific type of problem
Can anyone describe what is going on here?
$$Si(liq.)=Si_{(1 weight percentFe)}$$
I have come across this statement quite a few times in Metallurgical Thermodynamics.All that they ask for is change in ...
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Properties of inconel [closed]
I am doing a project on the physics of the spaceX raptor engine. I believe it is made out of a certain type of inconel alloy. I want to understand why this alloy has the properties that it does, but I ...
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How to refine manganese metal from manganese(IV) oxide found in batteries? [closed]
I opened up some lantern batteries, and inside there's $\ce{MnO2}$ powder, carbon rods, and zinc casings, and other stuff that I don't know what it is exactly. I scraped out $\ce{MnO2}$-containing ...
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Thinking of reducing aluminum hydroxide with magnesium
Is it possible to reduce aluminum hydroxide to aluminum metal by using a sacrificial magnesium electrode in a single displacement reaction?
I checked my revision of redox charts and it looks like it ...
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Origin of the 15% difference limit between solute and solvent atom radii in the Hume-Rothery rules
According to the Hume-Rothery rules for the substitutional solid solutions the atomic sizes of the the solute and solvent must not differ by more than 15%.
Why should it be so?
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