Questions tagged [metallurgy]

Metallurgy is the science of the production and the processing of different metals and other metallurgic usable elements.

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18 views

Heat treatment processes in Nickel-Based Superalloys?

What is the difference in heat treatment process between Wrought Ni-Based superalloys &cast Ni-Based superalloys
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Why is carbon boil even necessary?

Particularly in an Electric Arc Furnace I have seen carbon boil occuring . I understand the reaction is very vital but what is it's utility? A detailed answer to this is most welcome. The internet ...
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37 views

What does time temperature specifically give us? [closed]

What is a Time Temperature curve basically? I have come across this a couple of times while dealing with heat treatment in my industry. A detailed reply to this is most welcome.
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Why is manganese steel non magnetic in as cast condition? [closed]

Is it because of some ferrite stabilizer or something?A detailed explanation to this is most welcome.
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What impact does reduction internal stress cause?

I have noted that recovery primarily reduces the internal stresses of the material.What is particularly confusing is why would that work out.A slightly detailed answer to this is most recommended.Also ...
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Why does decrease in dislocation density result in higher ductility?

Why does a decrease in dislocation density result in decrease in yield strength and increase in ductility?A slightly detailed explanation is what I am looking forward to.
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Unknown metal-piece connected to the case of an iPod Nano 2

I disassembled an iPod Nano 2 yesterday and was surprised to find a round brass-coloured plate glued to the back. I didn't find any mention of it at the teardown over at ifixit.com, as they didn't cut ...
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1answer
77 views

What is meant by soaking time in heat treatment?

After heating at 950°C and holding the temperature for 3 hours there is a soaking time that is provided for 12 hours. What is the soaking time being referred to here? A detailed reply to this will be ...
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A question on how heat treatment is done in bogies

During heat treatment of metals I find that Normalizing is done in railway bogies and tempering is done following normalizing only for the CP top and bottom. Following the tempering process quenching ...
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1answer
60 views

What is the characterising difference between a riser and a runner?

The image given below shows a bolster with a series of riser and runner. What I really do not understand is which is the riser and which is the runner. Also a detailed explanation to why multiple ...
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1answer
53 views

How to evenly heat stainless type 304 steel bar to approximately 200F?

I need to heat stainless bar stock prior to bending in a forming machine. I would like to reach approximately 200 degrees F. The material is stainless type 304/304L, 3/16" thick. We are heating ...
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36 views

How could you produce large quantities of metallic hydrogen?

Could you somehow crush hydrogen atoms with magnetic fields in order to produce it? Or maybe someday someone will invent a material capable of withstanding 500GPa and we'll have giant machines that ...
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1answer
329 views

Can Rotary Friction Welding be used to join metals and ceramics?

Is Rotary Friction Welding a good method to join cylinders of a metal (such as Ti alloy) and a ceramic (such as SiC). I know that Diffusion bonding can be used in such cases. However, it has its own ...
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What is the effect of Aluminium nitriding in steel?

"The most significant effect of AlN in steel is on grain size control, which directly influences hardenability, hot ductility, texture development, and mechanical properties."I have read ...
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Burrs on the wire surface after drawing

I have been involved in wire drawing for some years now. But only recently, I noticed that the wire surface was uneven and had burrs when inspected under a microscope (see photos). The wire is a Ni-Fe ...
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Fluid energy mills with powdered reactive metals

Can fluid energy mills manufacture spherical powdered metal of size ~5 micrometers in cases where the metal is quite reactive, like with lithium and aluminum, if the fluid used is a non reactive gas ...
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1answer
29 views

Question about a particular statement on plastic deformation of single crystals

"...the wider the dislocation, the lower is the elastic energy of the crystal because the atomic spacing in the slip direction is closer to its equilibrium spacing." What has elastic energy ...
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What is relationship between dislocation width and interfacial and elastic energy?

Let us say I have a defined dislocation width,now how would the interfacial energy and elastic energy vary when the dislocation width is more or less.I feel having a wider dislocation would mean bonds ...
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How is calcium and aluminium wire feeding different from each other?

How is Aluminum wire feeding different from that of Calcium wire feeding as far as the purpose is concerned also what I do not understand is what has wire feeding to do with the purpose and how are ...
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Doubt in triaxial stress state in a notched specimen

In the book titled "Mechanical Metallurgy" written by G.E.Dieter I am having problems to understand why a notch in a material would mean a triaxial state of stress.I do well understand that ...
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Why does corrosion take place at certain stressed regions?

Why does certain parts of metal show more corrosion at the place where there is high dislocation density in comparison to the place where the dislocation density is less? I do sincerely feel that this ...
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1answer
688 views

Is it possible to determine how the steel was made, having its microstructure (for example, to distinguish forging from rolled products)?

How do you think the steel in these images was made? Example1 (https://i.stack.imgur.com/oZLRM.jpg) Example 2 (https://i.stack.imgur.com/jrDE7.jpg) Example 3 (https://i.stack.imgur.com/fpl2d.jpg) ...
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1answer
31 views

Tempering 1095 steel

I have some laser-cut filing templates, about the size of a business card, made from 3mm-thick 1095 carbon steel. These parts will be used to guide a round metal file when filing odd shaped holes in ...
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5answers
76 views

Why do you need helicoil if you can just use a tap?

I'm new to thread repairs and I was just wondering when using a helicoil, why does the helicoil need to be inserted if you have already tapped the new threads into a hole? Can't you just put a bolt in ...
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Is thermal conductivity a property that affects the use of an alloy in high-temperature applications?

I'm interested in the effect of thermal conductivity on the choice of materials used for high temperature applications such as turbines. For the particular case of Nickel-Chromium alloys (such as René ...
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Finding fraction of liquid and solid from isomorphous alloy phase diagram

if alpha of 82% B and liquid of 57% B are in equilibrium in an alloy of 73% B,the fraction of liquid is? I know formula for it, but confused in finding property. Any help will be of great use & ...
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Extracting other mineral from salt in evaporated seawater

I recently stumbled upon this news, seawater contains 47 minerals and metals. Starting with the most abundant and proceeding to the least abundant, these are chloride, with a concentration of 18 980 ...
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1answer
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Can a threaded fastener stretch so much it can be miss-read as a different pitch?

Can a threaded stud of mild steel, size 5/8"-11 over a threaded portion of 1.25" stretch so much over time that it reads 5/8"-13? Unthreaded portion of the stud reads .625-630" in ...
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1answer
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Where to find a list of hard low melting point alloys?

Im looking for alloys that have a melting point lower than 600°C and as high as possible hardness. Is there a search engine I could use to find those alloys with their physical properties?
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2answers
64 views

What alloy am I making (Al-Bi)

I have been melting aluminum in a DIY furnace for a few months in order to make lost wax casts. I was thinking that since bismuth has a much lower melting point than aluminum, that I could add a small ...
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1answer
67 views

Purpose of a GD-Zn alloy

Here are screenshots of the data-sheets of two separate products for a reference. They both are nickel plated, used for coupling nuts. The former is shielded, the latter is not, I wonder if this is ...
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1answer
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I have a small piece of stainless steel that I need to remove 1-2mm of material. The hardness is 200. What type of file do I need to get?

This is a part of a mounting system for an Olight pistol flashlight. The universal adapter that they include isn't so universal when it comes to a Canik handgun. I've talked to the people at Olight ...
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1answer
51 views

What's the benefit of copper plating paper clips?

(Sorry, not an engineer or student, just looking for the most metallurgically relevant stack.) Recently I was in someone's office and, while playing with their paper clips, it occurred to me that ...
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Is it possible to silver solder a reliable grounding connection to a stainless steel ultrasonic cleaner tank?

My ultrasonic cleaner has a stainless steel tank with a threaded grounding stud for fastening a mains earth wire. I tried to tighten nut that fastens the ground terminal to the stud, but the stud ...
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How to rule-out if there's lead in a pipe's alloy?

I have a 2" diameter, 6" long pipe that I believe to be steel and want to use IF it is, heck I want to use it if it's OK to handle (ie not lead, arsenic etc..guess I can only rule-out so ...
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1answer
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Can the US realistically mine and produce all Rare Earth Elements, without relying on China? [closed]

Why exactly isn't the US mining and producing its own rare earth metals (REEs)? I'm baffled by the mixed messages below. Because China uniquely possesses some REEs? US safeguards against pollution ...
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Is inverse hall-petch relation valid crystals larger than nanocrystalline?

The image shown here is of ceramics, where they varied the grain size and measured the strength. For example, let's take Al2O3. There we observed that strength first increased from 3 μm to 95 μm. But ...
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Non-toxic material for deformable wire/rod without work hardening

I am looking for a non-toxic material for a wire/rod that allows room temperature deformations without work hardening. Example uses are semi-rigid cables that one can bend and that hold their shape ...
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Why is a mold required in isostatic pressing after performing Sintering

After an a object is formed through direct laser sintering, as a post-processing procedure the object is sent for hot-isostatic pressing, In hot isostatic pressing the sintered object is placed in a ...
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How to increase blast furnace top gas temperature?

Why does blast furnace (in Iron & Steel works) top gas temperature stays low and what are the fixes for that to increase without using a burner? The top gas temperature goes below 80 degrees (...
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1answer
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Is there any way to improve the strength of simple at-home aluminum/copper/brass castings (sand-casting hammers)

I'm just getting-into melting-down cans to make aluminum-based slingshots, hammers and the like. In my ignorance I didn't realize that copper/brass were also things that I could process which has ...
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48 views

Precipitation Hardening

Please explain the meaning of this statement with close reference to Precipitation hardening,"The relative rates of nucleation and growth are controlled by temperature. The size and dispersion of the ...
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3answers
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(moulded) cast properties of the untreated surface

While my research about the untreated surface of moulded cast I read that the properties such as tensile strength, 0,2% proof stress and so on are different (much smaller) from the properties you can ...
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Effect of annealing on the defects

What is the effect of annealing on the defects present in the sample? Does it remove defects in the sample? Is there any chance that due to annealing the point defects present in the sample combine to ...
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Is it possible to cast copper around another metal

So i have seen these super conductor rods around (which appear to be copper around titanium/niobium). Now I am wondering (for a maker usecase) if its possible to create something similar by for ...
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Electric Current Based Shape-Memory Alloy

Would it be possible to create a piece of metal, made out of an alloy or combination of alloys, that undergoes a shape-memory-esque change in structure in reaction to an electric current? Could it ...
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1answer
37 views

Fastening rotating surfaces

This is probably very well explained but I'm lacking the terminology knowledge and that's keeping me from finding the information I need. I have a frame to which I need to attach a weight carrying ...
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How to produce aluminium powder by E. J. Hall method

I have watched videos on YouTube producing Aluminum powder by mechanical methods. Like this one. It uses Aluminum foil and coffee grinder: There are similar videos which use the same basic method but ...
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Why do Blast Furnace flue dust generates high rates of Zn (Zinc)?

The Blast Furnace flue dust contains high rates of Zn (Zinc). I'd like to know the reason behind this. The chemical reaction of Zn inside blast furnace dust. Why it's rates becoming high?
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How do old wind turbine towers pickup magnetism overtime?

I was conducting some robotics tests on a old wind turbine today, and noticed strong magnetic fields around the steel tower. This magnetic field does not exist on other modern wind turbines at the ...