Ignition characteristics of energetic nichrome bridge initiator based on Al/CuO reactive multilayer films under capacitor discharge and constant current conditions

Abstract

Four types of Al/CuO energetic nichrome bridges (ENCBs) initiators are reported, prepared by integrating Al/CuO reactive multilayer films (RMFs) on different V-shaped nichrome bridges (NCBs) through magnetron sputtering technology. V-type angles of NCBs are 150°, 136°, 120° and 90°. The fabrication, electrical explosive characteristics of these ENCBs initiators under capacitor discharge, as well as its firing process under constant current conditions are systematically described. The results reveal a ‘stagflation’ phenomenon in high-speed photograph of ENCBs at low discharge voltage, which is consistent with the result of optical microscope images. It is noted the electric explosion delay time decreases with an increase in the discharged voltages, while the critical ignition energy has no relationship with discharged voltages. Moreover, among the four ENCBs, the one with V-angle of 90° exhibits the shortest electric explosion delay time and lowest critical burst energy. This suggests that the electrical explosion performance of ESCBs can be adjusted by optimising the V-shaped angle and the discharge voltage. At last, the high combustion efficiency of ENCB is proved by comparative test with NCB at 0.6 A. And ENCBs have better heating efficiency than nichrome wire with the same resistance at 0.4A and 0.6A.