Design of Superelastic Nitinol Enhanced Puncture Resistant Armor

Proposed is an investigation into the use of flexible, extremely strong and tough, superelastic Nitinol shape memory alloy as a means of dramatically improving puncture resistance for personnel body armor. The Nitinol material is proposed as a surface material or coating for reinforcement or organic fiber fabrics and/or composites or aramid and UHMW polyethylene used in the current body armor systems for military and police personnel. These Nitinol enhanced material systems will benefit users by providing bullet blunting protection and deflection without dramatically increasing the weight of the lightweight composite protective clothing. The armor would benefit from the improved cut and puncture resistance and improved flexibility that the Nitinol would give the protective clothing over present fabric and material systems used. Superelastic Nitinol is a flexible (almost rubber-like), very tough (4 time the stored energy of high strength steel) metal alloy of nickel and titanium. Known for its shape memory response at one temperature phase, Nitinol exhibits a superelastic (fully elastic and recoverable strain limit of 8-10%) response when used in the appropriate temperature phase. In the superelastic phase, tests have demonstrated its ability to increase puncture resistance for certain materials by 100%.