Study On The Preparation And Catalytic Performance Of Nano CoFe₂O₄,NiFe₂O₄ And Their Aluminum Powder Composites

Both nano metal oxides and nano thermite can effectively improve the burning rate and pressure expronent of solid propellant. In this paper, spinel cobalt ferrite and spinel nickel cobalt ferrite with various morphology and particle size were prepared, the effect of nano Al composites on the combustion performance of composites propellant was studied.Nano CoFe2O4 with particle size of 30nm and 50nm were prepared by hydrothermal method, the irregular rod CoFe2O4 and irregular nanoparticle NiFe2O4 were prepared using heating reflux method, CoFe2O4/Al, NiFe2O4/Al composites as well as nano composites of the two materials and main components of solid propellant (HMX, NC, CL-20, RDX) were prepared by ultrasonic method. The composites and morphology of CoFe2O4, NiFe2O4 and Al/CoFe2O4, Al/NiFe2O4 were characterized using X-ray diffraction (XRD) and Scanning Electron Microscope-Energy Dispersive Spectrometry (SEM-EDS). DSC thermal analysis was employe.o study the catalytic properties of CoFe2O4, NiFe2O4, CoFe2O4/Al, NiFe2O4/ (?)n the thermal decomposition of main components of solid propellants, the kine(?).unction of thermal decomposition was calculated.The results show that CoFe2O4 with 50nm, CoFe2O4/Al with 50nm, NiFe2O4 and NiFe2O4/Al have no obvious effect on the peak shape and peak temperature on the thermal decomposition of HMX. The addition of 50nm CoFe2O4,50nm CoFe2O4/Al, NiFe2O4 and NiFe2O4/Al make the decomposition temperature of NC decrease by 5.21?,3.84?,3.44?, 3.38?respectively,meanwhile, the exothermic heat releases were increased by 143J·g-1, 293J·g-1,135J·g-1 and 103J·g-1 respectively. The addition of 50nm CoFe2O4,50nm CoFe2O4/Al, NiFe2O4 and NiFe2O4/Al make the decomposition temperature of CL-20 decrease by 4.66?,5.33?,2.41? and 5.19? respectively.The four prepared particles also make CL-20 decompose faster during the thermal decomposition process. The addition of six composites of 50nm CoFe2O4,50nm CoFe2O4/Al,30nm CoFe2O4,30nm CoFe2O4/Al, NiFe2O4 and NiFe2O4/Al reduces the apparent activation energy of thermal decomposition of RDX, which shows they have a certain catalytic effect on the thermal decomposition of RDX. Because of the difference of morphology and particle size between cobalt spinel ferrite and nickel spinel ferrite, the addition of 50nm CoFe2O4,50nm CoFe2O4/Al, NiFe2O4 and NiFe2O4/Al does not change the thermal decomposition mechanism of RDX, but the addition of 30nm CoFe2O4 and 30nm CoFe2O4/Al changes that of RDX.