Cant help answer this, but am also interested in Nitinol.
I would like to get in contact with you regarding spring materials, possibly including ceramics, as you replied
to one of my Q's. david.fowler@ainsworth.com.au
I need to find an ideal spring material.
Cost is not an issue, so it may be an exotic.
The material must not be poisonous, e.g. no Berylium Bronze. This material would ideally have a Finite fatigue limit (Endurance limit), or at least a high strength up to 10^7 cycles minimum. The product is...
In normal gearbox design, it is found that using better materials can greatly reduce the size and therefore weight of the whole product.
e.g. 2 gearboxes I've seen... one weighed 480 kg, and the other weighed 46 kg. they had similar specs. so look into the strongest materials, to reduce weight...
I think 10^7 is normally considered infinite life for ferrrous materials. 0.45 of yield strenght is also a commonly quoted Endurance limit. If you were to calculate the real stresses and include stress raising factors etc, and all the results are well below 0.45 of yield (If that is correct)...
