Shape Memory Alloys, a.k.a. Muscle Wire, nitinol, etc.

[DrHoneydew]

I have a whole slew of questions about Muscle Wire and related products that make use of shape memory alloys such as nitinol. I have had little success finding web-content related to that topic. Now, I am looking for an appropriate forum to post questions in. Electronics? Materials Science? ??? Any advice on where to begin to even ask questions would be great.

If anyone happens to know quite a bit about the stuff, my first question is regarding the overheating of the material. If I were to supply a constant current within the given recommended range to a strand of muscle wire in order to put it into its contracted state, how long can I keep it there without overheating it? I'm not supplying more than recommended current, but I am supplying it for quite a long time. In other words, how can I know how long I can keep the wire contracted?

I have many other questions, but I would love to know where to best ask them.

Thanks in advance to all who take the time to read this.

Cheers,
DHD

 

[israelkk]

If you supply a constant current within the given recommended range then there is no time limit. Just make sure the cooling conditions and the ambient temperatures are as stated. For other conditions you need to adjust the current resulting in different activation time.

Check

http://www.dynalloy.com

they make the muscle wires.

 

[EdStainless]

In some of these systems they use the resistance of the wire in a feedback loop to control the current and make sure that they don't over heat the wire.
How long will depend on the cooling in your system.

= = = = = = = = = = = = = = = = = = = =
Rust never sleeps
Neither should your protection

http://www.trent-tube.com/contact/Tech_Assist.cfm

 

[TVP]

There is an ASM affiliate society called SMST that is specific to shape memory and superelastic alloys. Use the following link for more information:

http://www.asminternational.org/MST...tentManagement/HTMLDisplay.cfm&ContentID=8131