Preparation Of Nanometer Metal Powders And Study Of Their Catalytic Characteristics

Nanometer Ni, Cu and Ni-B amorphous alloy powders, the particle sizes of which were about 50nm, 20nm and 20nm respectively, were prepared by chemical reduction. The optimal condition to prepare nanometer nickel powder is showed as follows: PVP was chosen as surfactant, pH value was controlled at 9.5 and NiCl2 was added 5min late after mixing and heating all agents except NiCl2 solution. DTA results showed that they had catalytic characteristics on the high temperature decomposition of ammonium perchlorate. Nanometer Ni, Cu, Ni-B and Al could make temperature of the high temperature exothermic peak of it decrease 113.5℃, 130.2℃, 64.9℃ and 51.8℃ and the exothermic heat increase 200.0%, 172.7%, 13.6% and 106.1% when 5wt% of four kinds of nanometer metal powder were added to micrometer ammonium perchlorate respectively. Among them, Nanometer Cu had the strongest characteristics on the high temperature decomposition as well as on the low one. The catalytic characteristics of micrometer metal powder were lower than that of nanometer ones although micrometer Cu and Ni had some catalytic characteristics. In the meanwhile, Nanometer Ni, Cu, Ni-B and Al had catalytic characteristics on the propellant samples and could make the high temperature decomposition decrease 14.7℃, 33.6℃, 23.3℃ and 31.6℃ respectively. Nanometer Cu had the strongest characteristics again. The catalytic theory was analyzed elementarily.