Energy absorbing shape memory alloys

Abstract

Impact resistant components and methods of protecting structures from impacts. The components are interposed between a potential point of impact and a structure to be protected. They comprise a shape memory alloy (SMA) exhibiting pseudoelastic behavior, and having a high strain to failure.

What is claimed is:  
     
         1 . An energy-absorbing component, comprising 
 a structural member comprising a shape memory alloy (SMA), wherein the SMA exhibits pseudoelastic behavior in response to impact loading,    wherein the component is part of a structure subject to impact loading.    
     
     
         2 . The component of  claim 1 , wherein the structure is an aircraft.  
     
     
         3 . The component of  claim 2 , wherein the component attaches a seat to the aircraft.  
     
     
         4 . The component of  claim 2 , wherein the component attaches an instrument to the aircraft.  
     
     
         5 . The component of  claim 1 , wherein the structure is selected from the group consisting of an automobile, a mine-resistant vehicle, a down-hole drill, a blast shield, and a building.  
     
     
         6 . The component of  claim 1 , wherein the SMA has a strain to failure of at least 50%.  
     
     
         7 . The component of  claim 1 , wherein the SMA has a strain to failure of at least 60%.  
     
     
         8 . The component of  claim 1 , wherein the SMA has a strain to failure of at least 70%.  
     
     
         9 . The component of  claim 1 , wherein the SMA has a strain to failure of at least 80%.  
     
     
         10 . The component of  claim 1 , wherein the SMA has a strain to failure of at least 90%.  
     
     
         11 . The component of  claim 1 , wherein the SMA has a reversible pseudoelastic strain of at least 3%.  
     
     
         12 . The component of  claim 1 , wherein the SMA has a reversible pseudoelastic strain of at least 5%.  
     
     
         13 . The component of  claim 1 , wherein the SMA has a reversible pseudoelastic strain of at least 10%.  
     
     
         14 . The component of  claim 1 , wherein the SMA has a reversible pseudoelastic strain of at least 15%.  
     
     
         15 . The component of  claim 1 , wherein the SMA has material properties determined by a secondary anneal of about 550° C.-800° C.  
     
     
         16 . The component of  claim 1 , wherein the SMA has material properties determined by cold working followed by a secondary anneal of about 550° C.-800° C.  
     
     
         17 . A method of protecting a structure from impact loading, comprising: 
 interposing a structural member between the structure and a point of potential impact, the structural member comprising a shape memory alloy (SMA), wherein the SMA exhibits pseudoelastic behavior in response to impact loading.    
     
     
         18 . The method of  claim 17 , wherein the structure is an aircraft.  
     
     
         19 . The method of  claim 18 , wherein the component attaches a seat to the aircraft.  
     
     
         20 . The method of  claim 18 , wherein the component attaches an instrument to the aircraft.  
     
     
         21 . The method of  claim 17 , wherein the structure is selected from the group consisting of an automobile, a mine-resistant-vehicle, a down-hole drill, a blast shield, and a building.  
     
     
         22 . The method of  claim 17 , wherein the SMA has a strain to failure of at least 50%.  
     
     
         23 . The method of  claim 17 , wherein the SMA has a strain to failure of at least 60%.  
     
     
         24 . The method of  claim 17 , wherein the SMA has a strain to failure of at least 70%.  
     
     
         25 . The method of  claim 17 , wherein the SMA has a strain to failure of at least 80%.  
     
     
         26 . The method of  claim 17 , wherein the SMA has a strain to failure of at least 90%.  
     
     
         27 . The method of  claim 17 , wherein the SMA has a reversible pseudoelastic strain of at least 3%.  
     
     
         28 . The method of  claim 17 , wherein the SMA has a reversible pseudoelastic strain of at least 5%.  
     
     
         29 . The method of  claim 17 , wherein the SMA has a reversible pseudoelastic strain of at least 10%.  
     
     
         30 . The method of  claim 17 , wherein the SMA has a reversible pseudoelastic strain of at least 15%.  
     
     
         31 . The method of  claim 17 , wherein the SMA has material properties determined by a secondary anneal of about 550° C.-800° C.  
     
     
         32 . The method of  claim 17 , wherein the SMA has material properties determined by cold working followed by a secondary anneal of about 550° C.-800° C.