Tuesday, September 3, 2019

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

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

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

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

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

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

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

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

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

Applied Science on Patreon: https://www.patreon.com/AppliedScience


  1. Hi Ben,
    I couldn't find an email address for you. I wanted to send you a private message. I hope you're able to see this comment :) Thanks!

    I've been watching your videos for years and I built a couple devices to liquefy air over the past couple years, totally inspired by you. I have a question for you if you don't mind.
    How important is having extra copper on the cold head of a Stirling cycle cryocooler? Without one, what exactly happens? Does the cold tip get too cold, reducing the yield? I would think that the colder temperature would just liquefy gasses even faster but I could be wrong. Seems to me like more surface area would just keep it closer to 77K but slow down the liquefaction rate per cm^2 over that larger area.

    I'm pumping in nearly 100% pure dry oxygen gas into my thermos in which the cold head is inserted (and the cryocooler uses nearly 300 watts) but I still can't even HALF fill a 2L thermos in one day. I'm wondering if surface area is the issue. The dry oxygen gas is actually WASTE gas from a second machine I have that produces medical grade liquid oxygen from ambient air. It uses the Joule-Thomson effect for its cooling.

    Any input would be so appreciated. I actually wouldn't mind having a conversation with you some time about gas liquefaction (if you're ever bored, haha!)
    It is such a huge hobby of mine. I was intrigued by cryogenic science since a very early age and I'm in heaven these days from finally (starting to) achieve that goal.

    Please let me know what you think Ben

  2. Hi Ben,
    I was wondering what model oscilloscope you use in your videos.
    And which one you would recommend as a "starter" setup.

  3. Very intriguing, you mentioned you left them for thirty hours. I am curious as to the minimum amount of time you would need to achieve the same results.