Air Temp Nitinol

[gadgetmall]

A Nitinol Test showing the Straightning force of one small piece  of the 40 foot roll . I annealed this piece and it will react wait warm water and body heat . http://youtu.be/63qyM0xIq4c

[b_rads]

@gadgetmall,
Your video is very interesting and really piques my interest.  I will order a small 5’ piece just to play with.  600 Celsius or 1112 Fahrenheit is a good bit of heat to shape the wire.  To simplify this for me, would you shape the wire into a fairly tight coil so that when heated, the wire will bend into the curve to turn your wheel.  Since the wire will shorten, I would guess this must be taken into account when determining the length of wire to use.  In my case, I have pilot lights on the water heater, furnace, and gas fireplace that run year round.  This seems to be a built in source of heat for such an application like this.  Please keep us posted on your project.
Brad 

[gadgetmall]

I am investigating that now . My spring nitinol motor came today to observe . I think the straight wire loop will work way better than a spring just by first observations . The Thermobile uses Straight Nitinol wire soldered in a loop . Another way i have devised is make small hook and hole on the ends to be joined and anneal it closed . you can also use glue.
Recently i have just used Maxwell Ultra Capacitors charged up . two in series and it will make two inches glow red . i use alligator clips to pull on the wire while heating to get  straight memory shaped and i use a small dentist pick tool to wrap the wire around using a vise grip to hold one end then hook an alligator clip to a pair of needle nose pliers to pull on the spring i make it turns red and i dunk it in a bowl of water . wala , homemade spring . getting ready to show a video of my 1.5 inch spring stretched out lifting a pair of lock piers up 7 inches or so .. You have to TRAIN  your Nitinol after you anneal it . with straight piece get it ice cold and bend it then alternate in hot water . do this at least 10-20 time . you will then have a Very Strong piece that can come back or transform at lower temperatures and more stronger reactions like the slap video i showed .Never bend hot or warm Nitinol. It will lose part of its memory and will not come back to the original shape . One guy did just that  here .http://www.youtube.com/watch?v=ONEpZEj6Ymk  notice his deformed spring .he pulled on it when in the  austenite state or parent state . you should only bend or pull your Nitinol in it's full  martensite state or cold. I really recommend you get the 40 foot roll. It actually works better than the air temp or the body temp packs . This wire can be annealed at different temperature  and gives you a wide range of transformation temps as well including air and body transformations . i like it . i have bought almost 1000 feet of this particular wire .comming soon . i don't want to run out of this material and need lots of it for experiments . one person sells 40 foot pieces of this special Nitinol for 19.99 us http://www.ebay.com/itm/330696040468?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649 .

here is another guys idea diagram . I think instead of rods here i could use Nitinol wire and have a homemade generator hanging putting some weight on the wire . but that is just guessing . 

[gadgetmall]

@gadgetmall,
Your video is very interesting and really piques my interest.  I will order a small 5’ piece just to play with.  600 Celsius or 1112 Fahrenheit is a good bit of heat to shape the wire.  To simplify this for me, would you shape the wire into a fairly tight coil so that when heated, the wire will bend into the curve to turn your wheel.  Since the wire will shorten, I would guess this must be taken into account when determining the length of wire to use.  In my case, I have pilot lights on the water heater, furnace, and gas fireplace that run year round.  This seems to be a built in source of heat for such an application like this.  Please keep us posted on your project.
Brad 

Hello . I have found the perfect Annealing procedure using the 40 foot roll nitinol wire . This wire is a golden amber color off the roll . You cant kink it as it will snap into . you can bow it but it is stiff and just goes back straight .. Some tell you 600c or 1122 c . That is BS . As far as i can tell you do not need to get the wire that hot . In Fact you will damage this wires Crystalline properties and mess it up permanentlyIf you get it much higher than 600-700 degrees F. Heres why thru experimenting i have found the perfect ANNEAL for my Nitinol wire . I took three pieces 6 inches long. the first piece i used three high amperage Ultra super caps at 2.7 volts each and used needle nose pliers connected to neg and pos and let the first wire glow red for a bout three seconds then disconnected it very fast and let it fall in a bowl of ice water . The transformation temp is high as it takes very hot water to transform . The second piece i used two ultra caps 5.4 volts and did the same thing except i let it barley glow then dunked it in ice water . the transformation now occurs at luke warm water ..Now the third piece i used only one 2.7 volt ultra cap .. I watched the wire change color from golden amber to blue,no glow then dunked it in ice water . Now i have air temp Nitinol and will change to the  austenite stage at room temperature and really fast using body temp and it only needs cool water not ice water to make it flexible and in the martensite state . So DO NOT LET THE WIRE GET RED .you only need enough heat to change the wires color then ice water to anneal it to make air temp nitinol. I have two IR digital thermometers coming soon so i will let you know the exact temperatures but i estimate 550 degrees F is the best annealing temp for a Nitinol Air motor .
Comprehensive studies have been done on the outcome of the transition temperatures from various annealing temps and stresses . One is here http://www.scientific.net/KEM.324-325.335 .

Also note that i used needle nose pliers and actually pulled on all the wires while heating to gain tensile strength as well as more movement .  I have tried the first few pieces without puling  strain using a torch  and the seemed weaker . There are lots of studies on this annealing using a force applied and this helps in TRAINING your wire . Once you have the proper annealed wire you want to smush it up in cold water and then dunk it in hot water 10- 20 time or more . This makes the wire much stronger in reactions and helps stabilize your transition temps.  I am uploading a video of the last two pieces and their reactions . the first piece i gave to my daughter as it is not usable and was a casualty of experimentation . DON"T OVERHEAT YOUR NITINOL . and don't waste your money on the 5 foot sections from the magic wire sold by kellogsresearchlabs .you get so much more from the other seller . 
Here is another pdf you can save on TRAINING your Nitinol wire. http://www.jameco.com/Jameco/Products/ProdDS/357798.pdf
Gadget

[gadgetmall]

This is a video of My last two best samples of the same wire annealed at different temperatures  . The audio is out of sync with the Video and skipping a bit . Sorry youtube upload problem ..the first piece i let get red hot for a few seconds is now a toy for my daughter .

http://youtu.be/UzudyF0oNRQ



More Links and a Pdf from Cornell http://www.ccmr.cornell.edu/education/modules/documents/Nitinol.pdf

I tried to find out how many Electrons neutrons and protons are in this metal because i wanted to know the thermoelectric properties and came up with this link http://cst-www.nrl.navy.mil/lattice/struk/NiTi.html . This stuff can be combined in crystal cell batteries and piezo electrics . More test for that aspect later ...

gadget