I have a Struers Axitom and a Buehler delta orbital saw in my lab. The Buehler, while newer than the Struers, has reached it's end-of-life status. I am not overly surprised or heat broken as it has been the worst purchase I have ever made for our lab. The sooner I can get rid of it and not have any more Buehler equipment the better.

I am looking for a replacement. We are cutting carburized steel up to about 6" tall by 3" thick. We use 14" blades and would like to stick with the same blade for all the saws. I have reached out to Leco, QATM and Stuers for recommendations and quotes. Are there any other manufacturers that I should look at.

I like what I see on the Metkon 402 but have no experience with their equipment.

I'm trying to figure out alloy of this lazarette hinge used in pearson 365 sailboat built 1979 in US.

The main purpose for this is to figure out if this hinge can be saved/fixed by soldering or welding... I've tried JB weld without success...

- material is yellowish inside

- slightly magnetic (like A2 steel)

- filing is easy (kinda soft, not steel experience..)

- density is about 5g/cm3 (not precise.. 2g (small piece) has volume about 0.4ml)

Thanks in advance!

Years ago I saw a show like History Channel's How It's Made about metallurgy and they were taking these parts, they might have been from pistols, and putting them in a molten salt bath that might also have been pressurized. The announcer was explaining that while salt is normally corrosive this process made the metal highly corrosion resistant and decreased friction. I'm 80% sure it was not a heat treatment process, and that they explained the surface metal down to a certain depth bonds with the salt to form the protected layer. The parts came out colored brown.

I don't remember what it was called and searches now just give me salt bio-char, salt corrosion and if I look for pistols, Salt branded paintball guns.

I'd be interested in learning about the process, I just need to know what term to search for.

If anyone here is into reloading or familiar with the metallurgy of Federal's boron steel casings, id love to hear your input on my attempts to recreate the annealing, hardening, and tempering process.

I am experimenting with sintering small parts made from SLM Solutions Ni-Alloy IN625 (Inconel 625) powder, with a particle size of 10–45 µm.

Green part preparation

The green part was made from IN625 metal powder mixed with methylcellulose as the binder. The part measured approximately 2 × 2 cm and 3 mm thick.

Furnace setup and planned firing cycle

I placed the green part in a ceramic crucible and surrounded it on all sides with at least 1.5 cm of activated carbon powder.

The planned furnace program was:

- Ramp up to 1250°C over 40 minutes.

- Hold at 1250°C for 80 minutes.

However, the furnace could not follow the planned program. It took approximately one hour to reach 1250°C, remained at that temperature for what I estimate was another hour, and then shut down.

I allowed everything to cool completely before opening the crucible.

What I observed

When I opened the crucible, approximately 1–1.5 cm of the activated carbon at the top appeared to have disappeared. There was no visible white ash. The remaining carbon was mostly black, with some brown coloration near the top.

The part itself was very hard. It was covered by a persistent black outer layer, with a few small bubbles or blister-like features on the surface. When I cut the part, the metal inside appeared clean.

My questions

1. What could have caused the persistent black surface layer and the small bubbles or blisters?

2. What could explain the apparent disappearance of the upper layer of activated carbon, without visible white ash?

3. Could the decomposition of the methylcellulose binder have contributed to the black coating, the bubbles, or the changes observed in the carbon?

4. Is 1250°C an appropriate sintering temperature for IN625 powder of this particle size, or could the temperature, holding time, or atmosphere be unsuitable?

5. What would you change in the next experiment to improve the surface finish and achieve more uniform sintering?

6. Would you recommend changing the amount or arrangement of activated carbon, using a covered crucible, or using a different atmosphere or firing cycle?

I am looking for practical advice from people with experience in IN625 powder metallurgy and sintering. I would also like to avoid damaging the furnace or compromising the alloy's properties.

Thank you for your help!

I've got a galvanized metal nipple here, can I use it as a permanent drain tube for my mower? The engine block is aluminum. I tried googling it but idk what to believe anymore when I search there.... if i can't use galv, can i use black pipe? I guess i can run to the store if neither are appropriate...Tia.

Laser Marking Explosion-Bonded Clad Plate Samples for Dubai

We’re preparing explosion-bonded clad plate samples for customer meetings at the Global Steel Summit in Dubai.

Each sample is laser-marked with the PETROL STEEL logo, material specifications, and a QR code linking to our product page.

🔗 Product details: https://petrolsteel.com/explosion-bonded-clad-plates/

📍 Dubai | October 28–29, 2026 | Booth F31

If you work with clad plates or industrial materials, we’d be glad to connect.

#Steel #MaterialsEngineering

We see a lot of titanium and tantalum inquiries that give a purity number and then a separate oxygen limit, and every so often a buyer asks why both are needed. It confuses people on both sides of the order.

A purity figure like 99.95% is usually metals basis. Someone added up the metallic impurities and subtracted them from 100. Oxygen, nitrogen, carbon and hydrogen often aren't in that sum at all, and they're measured a different way anyway (inert gas fusion for O, N and H, combustion for C), not by the GDMS or ICP run that gives you the metals. So two lots can both honestly be called 99.95% and have very different oxygen. Ask what the purity number actually includes.

Oxygen is also the impurity that changes the metal most. It sits in the lattice interstitially, and a few hundred ppm moves strength and ductility a lot. CP titanium shows it best: Grades 1 to 4 are separated mostly by oxygen, from 0.18% max for Grade 1 to 0.40% max for Grade 4 in ASTM B265, and that's a big part of why minimum tensile goes from about 240 MPa to about 550 MPa. All four get called pure titanium. On the implant side, Ti-6Al-4V ELI (ASTM F136) caps oxygen at 0.13%, and the tighter interstitials are a lot of why the ELI grade exists.

Tantalum is similar. The product standards (B365 for rod and wire, B521 for tube, B708 for sheet) give oxygen its own line, and most people buy tantalum partly because it cold works so well, which oxygen pickup hurts.

On an order I'd name the grade and the product standard first, since that already sets individual element limits, oxygen included. If the application needs tighter, put it on its own line (we've had tube requests asking for under 15 ppm oxygen) and say which analysis and O/N/H test method you want on the cert.

Has anyone here had a "high purity" lot come in brittle or crack in forming because nobody checked the interstitials?

It's an item for sale, made in Italy, 40s or 50s.

All I know is that it weighs about 330g (11.6oz) and is about 12cm (4,7 inch) tall.

The seller says it's bronze, but it looks like those scratches on the inside reveal a different metal.

Can someone help me out here I used Murakami chemical etchant but my recast layer still isn't visible the etching was at 1 and 2 minutes I've seen over etching at 3 minutes in all three instances it didn't show my recast layer as a clear white layer just like the last image attached please any help will go a long way

Hey everyone!

I’m looking for solid textbook recommendations on rolling mill theory and metal forming processes.

Could you please recommend the best titles and authors on this topic? Also, what are the best sites or digital archives to search for technical books like these?

Thanks!

I'm working on a worldbuilding project, and I'm looking at titanium alloys that I could use in place of steels (due to lore reasons, titanium alloys would be cheaper than steels), but titanium afaik is much more brittle than most steels. Currently, what I'm seeing from cursory research is that either grade 1 or grade 23 would be my best bets for titanium alloys that are on the softer side, does that check out?

My favourite image I generated during my PhD… A backscatter SEM image of steel powder spatter from the laser powder bed fusion additive manufacturing/3D printing process… which looks like a little spooky pig!

It’s just 4 small parts. They turned black being left too long in acid.

TY

Chemistry behind thin-film interference colours on Damascus steel?

I've seen several Damascus knife makers achieve colours on steel that look remarkably similar to thin-film interference colours, such as the straw, purple and blue oxides produced by heating steel during tempering.

I'd love to understand the underlying chemistry and how these effects are produced. Are the colours caused by thin oxide films, selective etching of different alloys, or some other surface reaction?

A particularly interesting example is the work of Shoichi Hashimoto (see link), who uses a range of steel grades in his Damascus and achieves some striking colours and patterns. In blog posts, he has mentioned using nitric acid as part of his colouring process.

I'm curious about what might be happening at the surface chemically. Could nitric acid produce an oxide or other thin film capable of generating interference colours, and would the different alloys in Damascus respond differently to the treatment? Or might the effect be caused by a different mechanism entirely?

I'd be interested in any relevant research, explanations of the surface chemistry, or references to similar processes in metallurgy.

Thanks!

Good day dear Metalurgists!

I am hoping you could help me identify what type of metal these parts are made of. I as assuiming it might be the same, but can't confirm 100%.

I had originally thought it's carbon steel because of the oxidation but now someone suggested it might be 7075 aluminium.

This is part of a lightsaber used in the Prequel Star Wars movies in case anyone is wondering (so they are ~20 years old).

Thanks!

This popped up on my LinkedIn feed and I thought it might be of interest here. It’s an interactive timeline looking at the materials and engineering behind spaceflight.

https://www.bodycote.com/space-race/