Shape metal alloys or called SMA’s are something I had never heard of. This subject matter may not even apply to many of us in the metal construction industry but I think it certainly does. The science behind 
this is incredible I do have to admit that. So correct me if I am wrong SMA’s can return to their original shape even if they are deformed or if heat is used as an application. I think that is really cool and can serve many applications in the future. So from what I read it seems there are two different types of SMA’s, nickel titanium and iron based. Now, while I may not be a professional on the metals trading desk it is safe to assume that nickel titanium is expensive and may not serve as useful as the iron based. Iron based SMA’s are more attractive in terms of the raw materials used and processing costs are a lot lower than the nickel titanium.
This is something that should take the metal construction industry by storm because according to Christoph Czaderski, of Empa’s Engineering Structures Laboratory, the process of pre-stressing is  a lot simpler through this method, making it cheaper than other techniques used. This could feasibly allow engineers to create structures that are pre-stressed – now that to me would be an accomplishment. You can read more about this story by clicking here.