I'm playing with a thermomagnetic engine idea, and am having a great deal of trouble finding a suitable carrier material. I'd like to find something
DIYable with a Curie temperature between 100 and 300 C, with lower being better.
Any suggestions for something that's Diy-able and doesn't cost >$1/gram like In and Gd?
Related: Could I make MnB by reducing MnO3 and Boric Acid with Carbon?
If you had some invar 36, it works at 280C or with less nickel even around room temperatures depending on the ratio of nickel to iron.
"Later in the same year Hopkinson discovered that a sample of 25% nickel steel furnished to him was practically non-magnetizable at ordinary
temperatures ... it retained its non-magnetic condition while being heated up to 700 or 800 C and did not recalesce on cooling from a high
temperature. But when the temperature was reduced to a little below 0 C, ferromagnetic properties appeared, which were strongly intensified by further
cooling. Moreover, cooling to -50 C with solid carbon dioxide effected such a transformation that, when the specimen was returned to 13 C, it was
found changed from a non-magnetizable to a decidedly magnetizable substance; and it remained magnetizable on heating until 580 C was reached. In the
neighborhood of this temperature it again became magnetizable and continued so on cooling to the temperature of the room. By these experiments
Hopkinson showed that the material can, at ordinary temperatures, exist in either of two quite different states. both of which are stable." (page 4)
If you can find alumel that might be something you would like.
[Edited on 15-12-2015 by Morgan]
Alumel would be perfect. I'll see if I can find some. Thanks!ElizabethGreene - 8-3-2016 at 08:51
Thread necromancy commence. Arise long dead thread, Arise!
I had difficulty locating a source of Alumel, but was able to get some from a company called Concept Alloys.
I've been playing with it and made a couple of thermomagnetic motors.
Revision 1, cycled a couple of times, but was not great. https://www.youtube.com/watch?v=HAhV68TuR9c
<iframe sandbox src="https://www.youtube.com/embed/HAhV68TuR9c" frameborder="0" allowfullscreen></iframe>
Revision 2 didn't work at all.
Revision 3 taught me that I didn't understand how magnets work. After I reworked it to actually physics, it works spectacularly. I see what I need
to change to make it go faster for r4. https://youtu.be/81lEgQs45z8
<iframe sandbox src="https://www.youtube.com/embed/81lEgQs45z8" frameborder="0" allowfullscreen></iframe>
Edit: How do I embed videos? The Youtube "share" code didn't work.
[Edited on 8-3-2016 by ElizabethGreene]gdflp - 8-3-2016 at 09:21
