I cast a bar of copper brackets I got at Home Depot into a bar, and I’m seeing flakes on the underside. Are these impurities in the copper?

(Also, I am not referring the greenish oxidation. I’m referring to the brown and gold separated flakes)

I've recently realised a piece of jewellery I have has been losing its shine. I've got it confirmed that with a mill certificate and XRF testing that it's ASTM F-136. Is there anything I should look out for/avoid when trying to gently polish it in terms of not ruining its properties (specifically implant safe). I've tried a gentle general purpose soap but it's not been very effective. What should I be cleaning it with? Also, what's the mechanism that is likely to have led to it losing its shine somewhat, and how is this "repaired" without ruining the metallurgical properties?

I have a BSc degree in materials and metallurgical engineering but my school is heavily focused on metallurgy. If I want a career in research and development (probably in the industry) what should I focus in for Msc and PhD? Any tips or suggestions are welcome.

Was thinking of trying to use a Titanium alloy for making a women’s chain for a pendant. Anyone have any pros or cons?

I'm trying to understand the specs for a sample of ultra-fine electrolytic copper. There is an UF copper powder material in a small sealed ampoule that is labelled "PMS-M4." After some searching it likely refers to Russian "GOST 4960-75" regulation. The standard can be found in .pdf form online, but it's in Russian language. (if I'm using Reddit correctly, the link will be provided... but I don't post much so... Specifically, I'm trying to understand what this was manufactured for (end use). The analysis shows over four 9s purity...with a few ppm of Mo, W, Pb. I'm also wondering if these trace metals are doped additives (intentional), or just impurities. Can anyone here shed some light?

edited to include the link: https://inconsulting.com.ua/en/gosts/b56-hard-alloys-cermets-and-metal-powders/5151-gost-4960-75-electrolytic-copper-powder-technical-conditions.html

Hey guys I’m doing a casting project for a solder flange made of a semi-leaded red brass.

The allowable stress calculations I found in ASME BPVC Section 2 require information on the materials stress-strain-temperature relationship. Any idea what book, standard, article, etc I might be able to find it in? I have access to my school library so anything would work. Haven’t had much luck yet finding anything.

Im sorry if this is stupid question, or if im overreacting. I got a watch for my birthday. Its a seiko 5 watch and it says its made out of stainless steel. Im a bit worried to wear it since i know that people use lead in fake jewelry, and im not sure if it has any. It was bought from a jewelry store in my city(i live in Serbia), but i dont know if it guarantees that it isnt fake, and lead free for that matter. Once again sorry if the question is triggering or just plain stupid, but i just want to know.

Anyone know if you can use a plasma cutter on Manganese Bronze ?

So I was working with aluminum and after I was done I noticed that NY hands were silver and I tried to wash em up but some were still left that would shine in bright light on my skin , now there isn't much left but I'm asking if it is a health hazard that I touched aluminum dust without protection like gloves and mask and it will lead to health problems

The same with my lungs , is it a hazard that I didn't wear any mask ? ( I tried to sand the aluminum but stopped in less than a second cause I remembered I didn't have any mask and didn't go on )

Note that I don't work with aluminum regularly I can't recall the last time I worked with aluminum and any metal whatsoever

From my initial inquiries with copper rod producers, they measure their resistivity by four-point probe method. I was not really familiar with it, as I did not have background on electrical engineering. Upon searching, four-point probe method is mainly used for sheets. How would you recommend the measurement of resistivity for copper rod samples?

So i got myself some nice scissors, because I m into shiny cooking gear. Went into a hardware store and got some forged Steel scissors, but after cutting fresh kimchi with them for the first time they got dark spots (of corrosion?). Can someone enlighten me?

• the kimchi was fresh and unfermented
• ingredients of the sauce: fish sauce, fermented shrimp paste, red pepper powder, garlic, pear, rice flower, water
• solids that i cut: parsleyroot, napa cabbage, cellery, spring onion

Ok so I'm teaching myself how to weld tig weld titanium. They used to do it at the place I work but they have stopped. When the metal oxides and changes color from interacting with the atmosphere, ik it reduce the corrcorrosion resistance and some other things. Can I just reheat up the colored spot and keep it under argon and let the welding g arc clean it till it goes back to silver and would that give it back its corrosion resistance? or once you get color, can you not give it back the properties it lost from the contamination?

Pycalphad.. does anybody know how to install this.. i cannot findout the right way as they mentioned in web, also how to use this.. some one help me..

M21, I recently started working in a lead blast furnace as a process engineer. Heard a couple of rumours here that as lead is a toxic metal there are a lot of health issues that people have to deal with. If anyone has an experience in lead furnace can I please know how bad is it to actually work in a lead furnace and what precautions should I take to avoid these issues. Also what do I actually learn in this blast furnace? I have learnt the basic overall process but now I'm at a roadblock already in a month, it seems like there's nothing more to learn but I feel like there is a lot more to it than what I see.

Recently I casted a Cu-15Mn-8Ni-2Co-0,6Cr-0,3Nb-0,2Fe alloy. The idea was to make a Cu-Mn-Ni-Co solid solution with some NbCr2 and Chromium rich precipitates to make the material harder. I used a cast iron mold and couldn’t see much segregation, the alloy was also very soft and malleable in the as cast state. When the alloy was cold worked and heat treated between 750 and 900 Celsius and quenched in water a structure similar in appearance to austenitic stainless or alpha brass was obtained, and when slow cooled some phase separation seems to happen, maybe Cobalt or Manganese rich phases, but no significant improve in hardness. Image: as-cast structure 60x magnification

Hello there,

i have a quick question about the heat hardening process of Argentium silver.

It is advised to heat a piece of Argentium to 300°C for an hour and then let it air cool to achieve the precipitation hardening effects. After that it can be heated again to 100°C for a while to bring the germanium to the surface and passivate it via oxidizing.

Does the repeated application of the 100°C step over time (for a surface touch up) have negative effects on the initial hardening or are the 100°C too low to cause any change?

My facility has transitioned from pilot to r&d we had been processing titanium powder there for years.

This stuff is nasty and is absolutely caked on everything. Mopping it up doesn't seem practical. You'd need to change the mop water after every dunk. It would take an ungodly amount.of water and time to do it it like that. I have tried pressure washing it I have tried mopping it.

I am considering renting a walk behind floor scrubber. Do you guys think that would be practical ? Would it ruin the machine ? Titanium is technically a flammable powder could it react in the floor scrubber ?

How would you guys go about getting the floor cleaned of all the titanium residue ?

I'm taking a materials science course as part of my engineering program. I'm really enjoying it, but it's going by quickly and we don't get to go into as much details about some topics as I would want. My question is why does pearlite form as lamellae? We went over how it's just cementite layered with ferrite, and how carbon can be dissolved into FCC/BCC structures. But how is it so symmetrical within the grains? Is it because the carbon dissolved in the lattice acts as a regular point so that's why it's regular in appearance? Or am I just over thinking it? I find it quite interesting, but I was told realistically it isn't "important" for me to know.

Edit: typo.

Apologies for being a layman.

So high-end bike chains usually come with PVD titanium nitride coatings to decrease friction & wear.

Chains always come pre-lubed with whatever garbage lubricant the factory could buy in bulk. Meant to shield the metal from oxygen during long storage. If you're going to use hot wax as the lube instead, then you need to prepare the chain by thoroughly stripping away all existing grease.

When I got my current chain, it had a rainbow sheen from its coating, and was just about swimming in grease (about 1 mm thick). So the grease wasn't the cause for the thin film interference.

During degreasing with petroleum spirits (turpentine/white spirits/nafta), the rainbow sheen changed colours noticeably, with some areas going a solid colour instead.

Is it possible the white spirits are somehow damaging/de-bonding that ceramic surface coating?

At first I thought this was because it was grease being removed from the pores of the surface coating. This would change the speed of light inside the coating, altering the thin film interference.

But I compared the colour of it completely dry, and then immersed in turpentine, and there was no change in colour, indicating that short chain petroleum does not penetrate into the pores of the ceramic coating.

Did I just fuck up my brand new bike chain?

Hi! I have been wanting to know more about the indepth differences between cast and forged pistons for engines. When trying to dig deeper into this from basic google searches, you typically get SEO'd articles that are way too broad and don't cite a dang thing. When doing scholar searches, i end up finding articles that are too complex and may not even be what im looking for.

The pistons in my engine (2022 veloster N) are made of 2721 steel, i believe thats what the make of them is called. Though hyundai is known to heat treat their pistons terribly. Because of this, they have rod failure when pushing higher power, most on forums will say "simply get forged pistons", but ive also seen forged materials thrown arounf so much that it almost seems to be a marketting buzz word. Ive known before that a core component of what makes a metal higher quality is heat treating, and that's the baseline of what i wanted to know more about this process.

If you take 2721 steel, and cast it into a piston, then also forge a piston of the same steel, and heat treat them exactly the same, will they be as strong as one another? One of my friends who owns a forge and does light smithing has explained to me that as long as a cast metal is heat treated properly, it would essentially be the same as a forged metal of the same treatment and build, as heat treating determines the strength, quality, and grain flow (idk if im using this correctly) of the metal.

In addition, if there are differences, if you take the hypothetical above, does doing the same quality heat treatment to the same metal (Forged v Cast) actually provide a different result? And if so, how much different? This is one of those things where most google articles just spit out random and broad "Forged components are 37% stronger here!, 33% stronger there!" And dont really back these up with exactly what im proposing above. If someone could break this down, or if a study already exists about this, link it, that would be awesome!

Thanks a ton yall!

The dish is nice (1.8m big) and very light without any sign of rust or corrosion or damage so I'd love to keep it in good condition.

Hey there! I’m working on a system to atomize metal scrap into spherical powder for sintering, And I’m wondering if anyone has info or experience I can pick their brains about. An ultrasonic or gas atomization system seems the best but high pressure jets of argon might be quite tricky. Current idea was a small induction heater to liquify the steel that’s been ground into little chunks under an argon atmosphere, a crucible that allowes the metal to be pushed through a nozzle at the bottom, and a tower to allow the atomized metal to solidify into a spherical shape. The smaller the particle size the better. If anyone else has methods better used for small particle stainless steel I’d love to know.

I need to produce an alloy using a planetary ball mill, and the elements I have chosen are Al, C, Fe, Ni, Mn, and Cr. Does anyone know how to select the right parameters for planetary ball milling?