Cryogenic treatment of drill bits: tested 2X lifetime and microstructure analysis @AppliedScience

Uploaded September 2019 | Updated September 2026, 2 weeks ago

I bought some HSS stub drills, and treated half of them with liquid nitrogen, which improved their wear resistance dramatically. I also look at the change in microstructure with an electron microscope.

Performance of cryogenically treated M35 HSS drills - http://sci-hub.ru/10.1007/s00170-011-3616-8
Performance of cryogenically treated HSS tools - http://sci-hub.ru/10.1016/j.wear.2006.01.017
Effects of Cryogenic Treatment on the Strength
Properties - http://sci-hub.ru/10.1088/1757-899X/229/1/012014

LN2 generator video: youtube.com/watch?v=7PWESWqhD8s
Heat treatment of steel video: youtube.com/watch?v=ulfCxDsVTWo

Source of drill bits: mcmaster.com/catalog/125/2508

Temperature logger (discontinued, unfortunately): adafruit.com/product/3081

3M fine polishing pads: amazon.com/Tri-M-Ite-Polishing-Abrasive-Assorted-Sheets/dp/B07CP9CCH4

Delorean patent on cryogenic torsion bar: patents.google.com/patent/US4378658

Steel grain structure inspection, and overall great channel for material analysis: youtube.com/watch?v=UuHofNW40Yw

Steel grain structure video: youtube.com/watch?v=0SIr2sBHxA4

Applied Science on Patreon: patreon.com/AppliedScience

Cryogenic treatment of drill bits: tested 2X lifetime and microstructure analysis

DIY X-ray CT scanner controlled by an Arduino

Review of National Instruments VirtualBench

Hypercentric optics: A camera lens that can see behind objects

Atomic Layer Deposition of copper - If you like sputtering, youll love this!

Behind the scenes at Applied Science: Why video? Camera gear. Shop tour.

Milling machine tutorial - cutter selection, speeds and feeds, coolant, high speed machining

$Etching silicon wafers to make colorful Rugate optical filters (porous silicon) Passing an electrical current through a silicon wafer in a special acid etchant will create a porous layer with a variable index of refraction. I describe how this process works, and how the Fourier transform relates filter design to electrical etch waveform and resulting spectral response. Notes: 1. The Rugate filters look especially good in polarized light because the reflection from the silicon wafer is reduced, but the reflection from the filter remains strong. I noticed this while holding the wafer in front of my computer monitor. Later, when showing it to friends, the color intensity was poor. Their monitor must have been horizontally polarized, so holding the wafer low, and tilting it upward didnt work! Some monitors are horizontally polarized, and some are vertical. 2. The magnet used to hold down the PTFE cup to the wafer may have a very slight impact on the etch process. The dramatic shift in filter performance at the periphery is due to O-ring restricting the conductive etchant to a sharp edge, creating an electrical field concentration. Outstanding visual Fourier series tutorial: http://www.jezzamon.com/fourier/index.html LR-1 spectrometer: http://www.aseq-instruments.com/LR1.html p-type wafers on eBay. (You have to hunt around and check the photos for info on the label attached to the box of wafers. Be sure to get wafers less than 0.01 ohm-cm) eg https://www.ebay.com/itm/25-silicon-wafer-P-type-150mm-100-sumco/263441166009 n-type wafers are photosensitive during the etch process. Online graphing calculator page from this video: https://www.desmos.com/calculator/hiju8zdqfz Original Desmos page that I used: https://www.desmos.com/calculator/qpnz9celzf Code for Keithley 2450 control and processing.org waveform generation: https://github.com/benkrasnow/Porous_Silicon_Optics Fourier transform to understand optical coatings: http://www.willeyoptical.com/pdfs/92_180.pdf Porous silicon refs: https://www.rp-photonics.com/rugate_filters.html https://www.intechopen.com/books/porosity-process-technologies-and-applications/porous-silicon https://sci-hub.se/https://doi.org/10.1016/j.mee.2011.03.143 https://sci-hub.se/https://doi.org/10.1080/10408436.2010.495446 https://sci-hub.se/https://doi.org/10.1007/978-3-319-71381-6_2 https://sci-hub.se/https://doi.org/10.1364/AO.44.005415 https://sci-hub.se/10.1364/OE.16.015531 https://sci-hub.se/https://doi.org/10.1002/adma.19940061214 https://sci-hub.se/https://doi.org/10.1063/1.2906337 Silicon wafer identification flats: https://www.tf.uni-kiel.de/matwis/amat/elmat_en/kap_5/illustr/i5_2_4.html Applied Science on Patreon: https://www.patreon.com/AppliedScience$

X-ray timelapse of fluid movement in plants, stop-motion animation, sensor teardown/repair

Mutarotation: a sugar that spontaneously changes from sweet to bitter