Study On Fabrication And Performances Of Al/Ni And Al/Ti Multilayer Energetic Films

Al/Ni, Al/Ti nanoenergetic film materials were the novle energetic materials. Nanoscale energetic films could improve the ignition properties of transducer and ignition reliability and the safety of pyrotechnics because of the higher output energy. The best preparation, chemical reactivity and electrical explosive characteristics of Al/Ni,Al/Ti multilayer nanoenergetic thin films were studied in the paper and the study progress were obatained to foundate for the practical applications of Al/Ni and Al/Ti energetic bridge film transducer.Ni, Ti film surface morphology characterizations were characterized using FESEM. And the optimal preparation conditions of Ni film were obtained that sputtering pressure was 0.4Pa and sputtering power is 150W; optimal preparation conditions of Ti film was that sputtering pressure is 0.4Pa, the sputtering power is 150W. And also the deposition rates of Ni and Ti films were approximately 7.6 nm·min-1 and 5.0 nm·min-1.Al/Ni nanoenergetic films were fabricated by Magnetron sputtering. And the surface was flat, the particles were uniformly dense. The layered structures of Al/Ni multilayer films were clear. Al and Ni film were all crystal structures in Al/Ni multilayers. The crystal structure of Al film was Al (111) crystal modifications and The crystal structure of Ni film was Ni (111) crystal modifications. The surface of Al/Ti films was also smooth. The crystal structure of Al film was Al (111) crystal modifications and The crystal structure of Ti film was Ti (110) crystal modifications.The exothermic reactions of the Al/Ni multilayer films with bilayer thicknesses of 50,100 and 200 nm were characterized by DSC. And the characteristic temperature of the exothermic peaks inreleased with increasing bilayer thickness. All the DSC curves have three major exothermic peaks in the temperature ranges of 500K-530K、 570K-650K and 670K-730K, respectively. The heat release of the exothermic reaction of Al/Ni multilayer films with bilayer thicknesses 50,100 and 200 nm were 389.43, 396.69 and 409.93 J/g respectively. All diffraction peaks of Al/Ni multilayer films reactants after DSC experiments indicated that AlNi was the final product of the exothermic reactions for Al/Ni multilayer films with a 1:1 atomic ratio, independently of bilayer thickness.Every activation energy of exothermic peaks of Al/Ni multilayer films had consistent laws presented by Kissinger and Ozawa methods. The activation energy of each film exothermic peaks rised with the increase of peak temperature and the activation energies were relatively close.The exothermic reactions of the Al/Ti multilayer films with bilayer thicknesses of 50,100 and 200 nm were characterized by DSC. All the DSC curves have two major exothermic peaks in the temperature ranges of 720K-770K and 950K-970K respectively. The heat release of the exothermic reaction of Al/Ti multilayer films with bilayer thicknesses 50,100 and 200 nm were 457.99,493.42 and 696.81 J/g respectively. All diffraction peaks of Al/Ti multilayer films reactants after DSC experiments indicated that AlTi was the final product of the exothermic reactions for Al/Ti multilayer films with a 1:1 atomic ratio, independently of bilayer thickness.Every activation energy of exothermic peaks of Al/Ti multilayer films had consistent laws presented by Kissinger and Ozawa methods. The activation energy of the first exothermic peaks was higher than the second exothermic peaks of Al/Ti multilayer films.The outbreak time and plasma duration time of Al/Ni and Al/Ti nanoenergetic bridge film series had the same relationship with the voltage. The outbreak time increased with voltage decrease and plasma duration time increased with voltage increase. The plasma duration time of Al/Ni and Al/Ti nanoenergetic bridge film was greater than Al, Ni and Ti bridge films with the constant charging voltage and the lead time was vrey large.The violent explosion was observed when nanoenergetic bridge films was ignited with the same charging voltage. The plasma generation time of Al/Ni and Al/Ti nanoenergetic bridge films was less than Al, Ni, Ti bridge films.But the duration of electric explosion time of Al/Ni and Al/Ti nanoenergetic bridge films was higher than Al, Ni and Ti bridge films. This results were consistent with the volt-ampere characteristic curves. Al/Ni and Al/Ti nanoenergetic bridge films had more drastic electric explosion, the high temperature splash particles from Al/Ni and Al/Ti nanoenergetic bridge films were about 5mm-8mm high, this scattering phenomenon was very important in the isolation research of micro ignition system.The electrical explosion temperatures of Al/Ni nanoenergetic bridge films with three different modulation periods were higher than the Al, Ni bridge films. The peak temperature of were all above 6000K. And Al/Ni nanoenergetic bridge films with the modulation period of 50nm had the highest electrical explosion temperature of 7000K. The results showed that alloying reaction between Al and Ni could improve the temperature of Al/Ni nanoenergetic bridge films.The electrical explosion temperatures of Al/Ti nanoenergetic bridge films with three different modulation periods were higher than the Al, Ti bridge films. The peak temperature of were all above 5000K. And Al/Ti nanoenergetic bridge films with the modulation period of 50nm had the highest electrical explosion temperature of 6000K. That could be due to the heat release in the exothermic reaction of Al/Ti multilayer films.