I need a few hundred small parts made from 316L stainless. I’m looking at local suppliers and also overseas ones, including Made-in-China.com. The prices vary a lot, so I want to be sure the material is what it says it is.

The order is too small for expensive lab testing. Is a handheld XRF scanner good enough to spot 304 passed off as 316L? Or is it better to send a sample to a lab? Also, can I trust the mill test certificate from a supplier I’ve never worked with?

Would love to hear what has worked for you, or what went wrong.

I’m a graduate student working on AlOx barrier layers for flexible QLEDs. My goal is to obtain transparent, insulating films with an O/Al ratio closer to the stoichiometric value of 1.5.
I’m using a metallic Al target with a pulsed-DC power supply. I’m testing on bare glass before applying the process to PEN film.
Baseline recipe
Base pressure: approximately 2 × 10⁻⁶ Torr.
Pre-sputtering: pure Ar at 50 sccm, 100 W, 40 mTorr, with the shutter closed. Originally 5 minutes; currently 10 minutes.
Heating: started at the beginning of pre-sputtering, with the heater set to 120°C. I haven’t independently measured the actual substrate temperature.
Deposition: 30 W, Ar/O₂ = 76/4 sccm, 10 mTorr, 10 minutes.
Pulse frequency: currently approximately 50.8 kHz. The pulse-width display is around 17, but I haven’t verified its units or whether it represents on-time or reverse time.
Post-deposition treatment: sputtering power off, O₂ increased to 30 sccm, heater maintained at 120°C for 30 minutes, with substrate rotation.
Results and observations
XPS performed by an external characterization facility gave an O/Al atomic ratio of approximately 1.18, compared with 1.5 for stoichiometric Al₂O₃.
Increasing O₂ from 4 to 6 or 8 sccm while keeping Ar at 76 sccm did not improve the optical appearance; the films became less transparent.
At 30 W, the discharge current used to be around 47 mA during deposition. Recently, it is approximately 50 mA in pure Ar and rises to 66–67 mA after adding O₂. The current is stable both before and after oxygen introduction, and I haven’t observed visible arcing.
Resistance readings with a Keithley 2400 and a four-point probe setup vary between approximately 20 MΩ and overflow. The displayed source current is 0.1 µA, with a voltage compliance of 21 V, so I’m treating overflow as a measurement limitation rather than proof of film quality.
Thickness measurements are still being checked because the measured step height depends on the region selected in the profilometer trace. I don’t yet have a reliable deposition-rate comparison between conditions.
What would you change first?
For an oxygen-deficient film, would you prioritize reducing target power, changing O₂ flow/working pressure, or adjusting the pulse settings?
Could the higher discharge current at the same power indicate a different target oxidation state or chamber condition? How would you distinguish these?
Is post-deposition exposure to molecular O₂ at 120–150°C likely to improve the bulk O/Al ratio appreciably? I’m considering 30 sccm O₂ at 50–100 mTorr for 30 minutes, without plasma.
Would extending pure-Ar pre-sputtering from 10 to 30 minutes help reproducibility if the discharge is already stable?
The eventual substrate is PEN, so high-temperature annealing is not a practical option. I’d appreciate suggestions for a controlled next experiment, especially from anyone who has deposited transparent AlOx using reactive pulsed-DC sputtering. Relevant papers would also be very helpful.

Hi everyone! Does anyone know how to make a material like the one in the attached photos and video?

It can be folded, twisted, and scrunched by hand, then holds the shape you give it.

My guess is that it uses aluminum foil sandwiched between layers. However, I’m worried that repeated bending and folding would eventually tear or crack the foil, making the material less durable.

Has anyone made or worked with something similar? If aluminum foil is the right approach, what thickness and bonding method would you recommend? Are there any more durable alternatives that would still hold their shape in the same way?

Any advice, material names, or tutorials would be appreciated!