Techniques for producing sma materials and powders

Abstract

Embodiments of the present disclosure provide improved techniques for creating SMA materials and SMA powders. SMA materials and powders formed may be used to form porous structures suitable for applications such as biomaterials, damping applications, actuators, and/or sensors. Embodiments for performing hydriding and dehydriding of SMA wires at low pressure and low temperature are provided. Methods may be used to produce a shape memory alloy (SMA) powder. Such methods may include hydriding a length SMA wire under low pressure for a period of time to produce a length of hydrided SMA wire, crushing the length of hydrided SMA wire to form a hydrided SMA powder, and dehydriding the hydrided SMA powder to form a dehydrided SMA powder.

1 . A method for producing shape memory alloy (SMA) powder comprising:
 hydriding a length SMA wire for a period of time to produce a length of hydrided SMA wire, wherein the hydriding is performed at low pressure;   crushing the length of hydrided SMA wire to form a hydrided SMA powder; and   dehydriding the hydrided SMA powder to form a dehydrided SMA powder.   
     
     
         2 . The method of  claim 1 , wherein the hydriding is performed using an acid, the method further comprising:
 monitoring, during the hydriding, a temperature of the acid; and   controlling, during the hydriding, the temperature of the acid during the hydriding, wherein the controlling maintains the temperature of the acid within a threshold tolerance of a target hydriding temperature during the period of time.   
     
     
         3 . The method of  claim 2 , wherein the target hydriding temperature is selected based on an alloy composition of the length of SMA wire. 
     
     
         4 . The method of  claim 2 , further comprising:
 placing the hydrided length of SMA wire in an ultrasonic bath subsequent to the hydriding; and   drying the hydrided length of SMA wire prior to the crushing.   
     
     
         5 . The method of  claim 1 , wherein the dehydriding comprises heating the metal hydrided SMA powder for a second period of time. 
     
     
         6 . The method of  claim 5 , wherein the hydrided SMA powder is heated in a vacuum furnace. 
     
     
         7 . The method of  claim 6 , wherein the hydrided SMA powder is heated in the vacuum furnace under an Argon environment. 
     
     
         8 . The method of  claim 1 , wherein the SMA wire comprises a nickel-titanium (NiTi) alloy wire. 
     
     
         9 . The method of  claim 1 , wherein SMA properties of the SMA wire comprise a directionality property, and wherein the directionality property is retained by the dehydrided SMA powder. 
     
     
         10 . The method of  claim 1 , wherein the dehydrided SMA powder, when incorporated into at least the portion of the article of manufacture, forms a sensor adapted to indicate a characteristic of an environmental stress acting on at least the portion of the article of manufacture. 
     
     
         11 . The method of  claim 10 , wherein the dehydrided SMA powder, when incorporated into at least the portion of the article of manufacture, forms a sensor adapted to indicate a characteristic of an environmental stress local to at least the portion of the article of manufacture. 
     
     
         12 . The method of  claim 1 , wherein the SMA wire comprises a magnetic shape memory alloy wire.