Air Temp Nitinol

[phwest]

Hi gadget and other experimenters.
This is a must see video and has a lot of important information
Mark


http://vimeo.com/45924783

Interesting looking constructions.  Shape Memory Alloys in general and Ni-Ti, in particular, a lot of research and work has been put into this back in the late 80’s.
Many military and civilian applications, patents issued, etc. a very versatile material and unique for certain solutions. (high pressure fittings in high stress high vibration environments, safety thermal disconnects etc).  Think of it as a one way bimetal that wants to snap when it reaches the transformation temperature and there is still heat transfer available to it. As opposed to a continuous smooth bimetal movement. It also requires a move-back external force to bring it back to initial shape upon cooling.

However; as far as free energy is concerned, all the research  and experiments so far have shown a much lower than 100% efficiency in heat energy to mechanical motion conversion.
Unless a new type of this alloy have been developed, the main issues are the transformation energy of around 24 J/gr and reliable strain cycle life expectancy.
Sure we can get 6-8% strain and recover but only for limited cycles. (it tires and would have to be retrained)
For less than 4% strain it can get to 100,000 cycles before “tiring” but to built a running machine, the strain needs to get less that 1.5% or less than 1% if we want to add some reasonable factor of safety.

Great material.
Good stuff, thanks for the flashback.

[gadgetmall]

Thanks for the comments . Nitinol has been tested but not much info has been released . One thing is for sure is it last and will never lose its programmed shape like you said IF the temp and stress parameters are always keep . It last millions and millions of cycles and will always return unless you stress it beyond its parameters . Also no one to date except me have actually had Nitinol annealed or pure enough to have 55f to 75 f full transition phase and posted their results  so in that respect Nitinol has improved And Nitinol AIR TEMP is Born .  . Nitinol will never wear out as proved by many experiments by the government and scientist as long as you do not stress it beyond it's parameters . Those are determined after its annealed and trained .In bearing lifing tests conducted by NASA in the 80's of Nitinol 60 , SM-100 has been shown to have over twice the life of 440C stainless steel and over ten times the life of conventional titanium alloys with a significantly lower coefficient of friction. The superelastic nature of the material gives it the ability to withstand compression loading of well over 350 ksi with no permanent yielding .

Gadget

[Tom Booth]

Hi, I have been researching and designing Stirling Engines for some time and recently discovered Nitinol.

One thing I haven't seen so far is a Nitinol Engine design that actually uses anything like a real Stirling Engine type configuration. That is, using a "displacer" to very quickly cycle between hot and cold.

I came up with this rough idea for a Nitinol Engine that - instead of having the Nitinol wire looping into separate hot and cold baths of water or whatever it uses a "displacer" or a diaphragm to move the Hot and Cold fluid (Air, water, oil or whatever) back and forth (or probably more practically; up and down) across the stationary Nitinol spring, wire or whatever.

I think a series of these could be coupled together on a crankshaft.

Anyway, here is a rough sketch of the idea.

[Low-Q]

I recently bought three varities of Nitinol Wire with reaction temps as follows . one is 115 degrees F the next is 98.6F and the third is the new AIR TEMP 70 DEGREES F . they all have infinate memory capibilities as long as the stress and memory temp parameters are met
mY  plans are to make a thermobile type motor with shafts to hold multiple pairs of Nitinol Wheels and connect the shafts to either a small motor/generator or put magnets on the shaft and capture the electricity with coils. The Nitinol can be Bought Cheap as a 300 foot roll cost 99 dollars . and 5 foot sections for 10 dollars . any one want to join in and get the Nitinol motor gen project ideas are welcoms . also any comments welcome . The "Heat" motor will use plain cool water and the outside air temp greater than 69degrees F to run the motor using AIR TEMP NITINOL. there will no need to heat up water as the air itself will supply the heat while the task will be to keep the cold side cooler so a 20 degree differantionl to run the motor . Now here on the East Coast i have recorded 116 degree air temp as we are in a Heat wave so heat is not the problem .Keeping the cool water might be . Possible using the earth ground as an insulator on the cold side of the motor and exposing the hot side to the air .
You can watch a Lecture about the properties and uses here .. http://www.youtube.com/watch?v=rZpZhSdgdSI&feature=endscreen&NR=1
Gadget

Actually, you don't need any specific nitinol to make a heat engine. I have nitinol wire with no memory. The wire is very easy to bend (but still super elastic) at room temperature or lower, but is hard to bend at higher temperatures. Sure this wire can help us capturing the power of different temperatures.


Vidar

[gadgetmall]

Hi Tom Booth and welcome aboard . I need another person interested In Nitinol . I have trained My nitinol to react in just AIR temps and no water or no HOT water should be needed . I like your design . I want to use the Earths Cool underground in the summer  . then use the Earths warmer underground(warmer that outside Winter cold) in the winter . at this point cool is the problem because of all the hot weather we have this year and i have no way to DIG a BIG hole in my yard yet;)

My Wire (i have rolls and rolls of this particular wire there is a difference) has noodle like stage at 50 degrees F and hard as steel stage at 75 degrees F .All my wire is Unannealed  so it must be conditioned before it can transform . I have mastered  the conditioning of THIS WIRE in any range as low as -10f to as high as 175f so this is a First time for any Nitinol to actually work without water ,just normal air .
Albert
AKA
Gadget