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
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Hi Ben,
ReplyDeleteI 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
Hi Ben,
ReplyDeleteI was wondering what model oscilloscope you use in your videos.
And which one you would recommend as a "starter" setup.
Thanks!
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.
ReplyDeleteJust wondering if you would be willing to do a video on induction? I would be curious to see how it works to heat up metal from a scientific point of view.
ReplyDelete