Questions tagged [metallurgy]

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

Filter by
Sorted by
Tagged with
3
votes
2answers
54 views

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 ...
2
votes
1answer
43 views

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 ...
-1
votes
1answer
16 views

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?
0
votes
2answers
56 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 ...
3
votes
1answer
40 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 ...
2
votes
1answer
37 views

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 ...
1
vote
1answer
49 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 ...
1
vote
0answers
16 views

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 ...
2
votes
4answers
53 views

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 ...
3
votes
1answer
70 views

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 ...
2
votes
0answers
9 views

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 ...
3
votes
1answer
59 views

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 ...
1
vote
0answers
12 views

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 ...
0
votes
0answers
63 views

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 (...
0
votes
0answers
16 views

In a sheet polymer/metal extrudate, why does the thickness varies while exiting the die and how much is the variation of thickness?

When a metallic or polymer/rubber sheet is extruding and leaving the die, it is seen that the variation of thickness occurs at the location of the die opening and at a distance far from the die ...
1
vote
1answer
27 views

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 ...
0
votes
2answers
41 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 ...
2
votes
3answers
66 views

(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 ...
0
votes
1answer
38 views

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 ...
0
votes
1answer
38 views

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 ...
0
votes
0answers
13 views

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 ...
0
votes
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 ...
0
votes
0answers
31 views

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 ...
0
votes
1answer
56 views

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?
3
votes
1answer
60 views

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 ...
1
vote
0answers
39 views

When were the japanese yellow/white/blue/silver paper steels introduced?

The steel series called kigami/shirogami (yellow/white paper steel, high purity carbon steels in different grades), aogami (blue paper steel, a tungsten alloyed tool steel series), aogami super (a ...
1
vote
0answers
26 views

Steel Worm/Steel Wheel vs Steel Worm/Bronze Wheel

I have a question regarding worm drives, specifically double-enveloping types: Do steel worm/steel wheel combinations last longer than steel worm/bronze wheel or steel worm/brass wheel combinations? ...
0
votes
1answer
39 views

Engineering standards or testing standards for hot punched metal holes for rolled steel

So, I have a problem with fatigue cracking originating from hot punched holes. From failure forensic reviews, it seems like surface conditions contributed to some of the failures, especially where ...
0
votes
2answers
55 views

What are equations related to the compaction of composite metal powders?

Say I am trying to create a metal composite and have a mixture of 3 different metal powders each with varying weight %'s. I'm going to compact them into the shape of a ring by applying a force P. The ...
0
votes
0answers
26 views

Phase prediction by cct diagram

Can someone please help in finding out the phase proportion of each phase w.r.t time , cooling rate and temperature by using (mathematical model to predict phases from given cct diagram) Leblond ...
0
votes
1answer
44 views

Kfactor for laminated steel plates rolling

I need to make a flat pattern for a cylinder made from a steel plate 44mm thick laminated with explosion cladding stainless steel plate of 8mm total plate thickness is 52mm. How I usually work is ...
0
votes
0answers
20 views

How to find phase proportion at equilibrium - from iron-carbon diagram - Leblond

{Equilibrium proportion P, this is the proportion which is reached at a constant temperature after an infinitely long time:P is also the austenite proportion in the case of extremely slow heating. It ...
1
vote
1answer
350 views

what actually cause quench cracking ? non-uniform cooling or rapid cooling?

It’s well known that quenching most alloyed steels starting from AISI 4140 to high speed steels in water, brine , or sometimes oil will cause cracking and distortions. in industry oil quenching ...
1
vote
2answers
245 views

What is the strongest and lightest material?

I have heard titanium is the strongest and the lightest material. It is used for my glasses frame. Is it true that it is the strongest and the lightest as well? Strongest, the biggest forces can it ...
8
votes
2answers
168 views

Can high alloy tool steels be quenched in brine?

It is will known that most of tool steels are quenched in oil to prevent cracking and distortion which appears when quenching in water due to non-uniform cooling caused by formation of insulating ...
2
votes
1answer
61 views

Is there is vanadium-free high speed steels?

Vanadium is present in all high speed steel grades. unfortunately vanadium not only very expensive but is also a will known cytotoxic metal. some workers get severe persistent cough lasts for months ...
0
votes
2answers
189 views

which type of casting will give higher cooling rate, casting in thin water-cooled copper mold or casting in thick copper die?

It is will known that increasing cooling of a metal casting will lead to finer micro-structure which mean higher mechanical properties. If I have 2 molds one is thick copper die ,& second is just ...
1
vote
1answer
1k views

What's the Difference Between LT and T Directions?

What is the difference between LT and T directions in MMPDS (formerly MIL-Handbook 5)? I hand understood that forming metal orients its grains, destroying the isotropic nature of 'pure metal' and ...
1
vote
1answer
558 views

Carbon Phase Diagram vs. TTT diagram

A "Carbon Phase Diagram" has an upper and a lower transformation temperatures. It was my understanding that once a steel had cooled below the lower transformation temp (1333 deg F) that the austenite ...
2
votes
1answer
993 views

What is the difference between work hardening and strain hardening?

I have come across the definition somewhere,"Work hardening, also known as strain hardening, is the strengthening of a metal or polymer by plastic deformation. This strengthening occurs because of ...
1
vote
1answer
5k views

Galvanized Steel (Zinc Plated Steel) vs Stainless Steel

Zinc Plating is known for its ability to prevent most corrosion, and it is done by just dipping a metal in hot pool of zinc and letting it cooldown. Meanwhile, stainless steel, an alloy that is ...
2
votes
2answers
447 views

Why are vacancies in solids called as equilibrium defects?

My professor, when discussing about Random Walk model during diffusion in metals said that "Vacancies are equilibrium defects but dislocations are not". I could not understand why. Why is it so?
0
votes
1answer
474 views

What is the most corrosion resistant 55HRC stainless steel?

55 HRC is a very high hardness, even for steels. Ideally the corrosion resistance of the steel would have to match AISI 316L or be even better. Qenched stainless steel can go to 55HRC. Even to 65 ...
0
votes
1answer
227 views

Which materials we can use for storing liquid nitrogen?

What are the materials we can use for the long-term storage of 30~liters of liquid nitrogen with composition and grade, along with the thickness of the sheet and storage capacity? Can we use any ...
2
votes
5answers
205 views

Is it practical to make a solar furnace for small scale metal production?

Solar furnaces using mirrors to concentrate sunlight on a small area do not produce much power - perhaps 1kW per square metre of mirror - but can reach very high temperatures. From the earliest ...
2
votes
1answer
440 views

Arc welder? Cheap welding device for chainmail/chainmail jewelry

I'm hoping this is the correct StackExchange for this question/request for advice. I'm looking to buy a welder to introduce me a little to welding, my main use-case right now is the hobby projects I ...
3
votes
2answers
40 views

Where does one go to produce custom metal objects?

I am wanting to produce custom mass plates for a project, very similar to those found in gyms. Here's a rough idea of what each one should look like: This is essentially identical to mass plates one ...
2
votes
1answer
59 views

Best way to manufacture stainless steel apparatus?

Shown in the images below I have designed a small stainless steel apparatus with accompanying hollow metal cylinders ontop. I'm looking into larger quantity production and simply CNC'ing these would ...
1
vote
1answer
552 views

What is strain hardening exponent?

Hardening leads to a material being more brittle.However I can't understand what is strain hardening or strain hardening exponent.Please explain why hardening leads to brittleness also in this answer ...
2
votes
2answers
108 views

38CrNiMoAlA: Does it even exist?

I have some plungers made of 38CrNiMoAlA. Their required hardness to be achieved via quenching/tempering is 51 HRC. I've scoured our technical order for heat treatment of steel alloys but the material ...