Reactive Characteristics of Novel Core‐Shell Al−CuO Microspheres Prepared by Alcohol‐Thermal Treatment of Cu(OH)2

Abstract

AbstractIn this study, core‐shell structured Al@CuO energetic microspheres are prepared through the alcohol‐thermal method. CuO is grown in situ around superfine Al powder, and Cu(OH)2 powder is used directly as the precursor for CuO growth. The effects of reaction temperature and reaction time on the chemical transformation as well as coating quality are investigated by using scanning electron microscopy, transmission electron microscopy and X‐ray diffraction. More importantly, the transformation of Cu(OH)2 into CuO during alcohol‐thermal process is tentatively discussed. And the growth mechanisms of CuO are speculated, which mainly consist of the continuous dissolution of Cu(OH)2, the transformation of dissolved Cu(OH)2 to CuO which happens at a lower temperature than that of dry Cu(OH)2 powder, and the heterogeneous nucleation and growth of CuO. The prepared Al@CuO energetic microspheres are compared with physically mixed Al/CuO counterparts by using thermal analysis, electric ignition and constant‐volume combustion tests. Benefiting from the improved interfacial contact quality, Al@CuO energetic microspheres show overall enhanced reaction characteristics in terms of reaction onset temperature, heat release, apparent activation energy, ignition delay, burning time and pressurization rate.