Apparatuses including hollow shape memory alloy particles

Abstract

An apparatus includes an elastic medium and hollow particles of a shape memory alloy (SMA) at least to dampen any of sound wave propagation through the elastic medium or vibration transmitted through the elastic medium. The hollow particles are incorporated into the elastic medium. The SMA has an Austenite finish temperature (A f ) that is lower than a temperature encountered in an application in which the apparatus is used so that the SMA exhibits stress-induced superelasticity.

1 . An apparatus, comprising:
 an elastic medium; and   hollow particles of a shape memory alloy at least to dampen any of sound wave propagation through the elastic medium or vibration transmitted through the elastic medium, the hollow particles being incorporated into the elastic medium, and the shape memory alloy having an Austenite finish temperature (A f ) that is lower than a temperature encountered in an application in which the apparatus is used so that the shape memory alloy exhibits stress-induced superelasticity.   
     
     
         2 . The apparatus as defined in  claim 1  wherein the hollow particles of the shape memory alloy have a distribution of wall thicknesses. 
     
     
         3 . The apparatus as defined in  claim 1  wherein the hollow particles of the shape memory alloy are spherical, randomly shaped, or combinations thereof. 
     
     
         4 . The apparatus as defined in  claim 1  wherein the hollow particles of the shape memory alloy have a distribution of sizes. 
     
     
         5 . The apparatus as defined in  claim 1  wherein the hollow particles of the shape memory alloy have a distribution of wall thicknesses and a distribution of sizes. 
     
     
         6 . The apparatus as defined in  claim 1  wherein the vibration is periodic and is within a range from about 1 hertz to about 200 hertz. 
     
     
         7 . The apparatus as defined in  claim 1  wherein the vibration is random. 
     
     
         8 . The apparatus as defined in  claim 1  wherein the elastic medium is selected from the group consisting of cis-polyisoprene, cis-polybutadiene, poly(butadiene-styrene), poly(isobutylene-isoprene), chlorinated poly(isobutylene-isoprene), brominated poly(isobutylene-isoprene), poly(ethylene-propylene), poly(ethylene-propylenediene), chloro-sulfonyl-polyethylene, polychloroprene, poly(butadiene-acrylonitrile), hydrogenated poly(butadiene-acrylonitrile), polyethylacrylate, poly(ethylacrylateacrylonitrile), ethylene acrylic, polysulfides, fluoro compounds (e.g., fluoroelastomers (FKM), perfluoro-elastomers (FFKM), or tetrafluoro ethylene/propylene rubbers (FEPM)), fluoro-vinyl polysiloxane, poly(dimethylsiloxane), poly(methylphenyl-siloxane), poly(oxydimethyl silylene), poly(polyoxymethylphenylsilylene), polyester urethane, polyether urethane, poly(propylene oxide-allyl glycidyl ether), polyether block amides, polyepichlorohydrin, poly(epichlorohydrin-ethylene oxide), and ethylene vinyl-acetate. 
     
     
         9 . The apparatus as defined in  claim 1 , further comprising a housing surrounding at least a portion of the elastic medium. 
     
     
         10 . An apparatus, comprising:
 a structure including two elastic medium layers;   hollow particles of a shape memory alloy at least to dampen any of sound wave propagation through the structure or vibration transmitted through the structure, the hollow particles being positioned in a space defined between the two elastic medium layers, and the shape memory alloy having an Austenite finish temperature (A f ) that is lower than a temperature encountered in an application in which the apparatus is used so that the shape memory alloy exhibits stress-induced superelasticity.   
     
     
         11 . The apparatus as defined in  claim 10  wherein the hollow particles of the shape memory alloy have a distribution of wall thicknesses. 
     
     
         12 . The apparatus as defined in  claim 10  wherein the hollow particles of the shape memory alloy are spherical, randomly shaped, or combinations thereof. 
     
     
         13 . The apparatus as defined in  claim 10  wherein the hollow particles of the shape memory alloy have a distribution of sizes. 
     
     
         14 . The apparatus as defined in  claim 10  wherein the hollow particles of the shape memory alloy have a distribution of wall thicknesses and a distribution of sizes. 
     
     
         15 . The apparatus as defined in  claim 10  wherein the vibration is periodic and is within a range from about 1 hertz to about 200 hertz. 
     
     
         16 . The apparatus as defined in  claim 10  wherein the two elastic medium layers are selected from the group consisting of cis-polyisoprene, cis-polybutadiene, poly(butadiene-styrene), poly(isobutylene-isoprene), chlorinated poly(isobutylene-isoprene), brominated poly(isobutylene-isoprene), poly(ethylene-propylene), poly(ethylene-propylenediene), chloro-sulfonyl-polyethylene, polychloroprene, poly(butadiene-acrylonitrile), hydrogenated poly(butadiene-acrylonitrile), polyethylacrylate, poly(ethylacrylateacrylonitrile), ethylene acrylic, polysulfides, fluoro compounds (e.g., fluoroelastomers (FKM), perfluoro-elastomers (FFKM), or tetrafluoro ethylene/propylene rubbers (FEPM)), fluoro-vinyl polysiloxane, poly(dimethylsiloxane), poly(methylphenyl-siloxane), poly(oxydimethyl silylene), poly(polyoxymethylphenylsilylene), polyester urethane, polyether urethane, poly(propylene oxide-allyl glycidyl ether), polyether block amides, polyepichlorohydrin, poly(epichlorohydrin-ethylene oxide), and ethylene vinyl-acetate. 
     
     
         17 . The apparatus as defined in  claim 10  wherein the vibration is random. 
     
     
         18 . The apparatus as defined in  claim 10  wherein each of the two elastic medium layers has an outer-facing surface, and wherein the structure further includes an outer layer positioned on each of the outer-facing surfaces. 
     
     
         19 . The apparatus as defined in  claim 10 , further comprising a fluid disposed in the space defined between the two elastic medium layers, wherein the hollow particles of the shape memory alloy are within the fluid.