Brief introduction of nano-aluminum powder

Dec 4 21:54 2013 David Yvon Print This Article

Aluminum is an active metal, at room temperature and air environments will automatically oxidize and form a layer of Al2O3 films, so that prevents aluminum further oxidized. 

This kind of surface passivation makes aluminum powder remain stable at a very high temperature. While the small size effect of nano-aluminum powder led to its performance changed.

 

Nano-aluminum powder shows many good properties,Guest Posting due to its advantages of small particle size, large specific surface area, high reactivity and so on. Studies found that the capacity of nano-aluminum powder combined with oxygen is stronger than ordinary aluminium powder. Nano-aluminum powder start oxidizing at 550, while ordinary aluminium was began to have clear oxidation phenomena at 950. Results showed that compared with conventional aluminium powders, nano-aluminum powder with lower ignition energy, can be directly ignited, combustion process without apparent cohesion, and full combustion. Compared with the ordinary aluminum powder, nano-aluminum powder has the characteristics of burning faster and heating larger and so on. The particle size, surface area, shape and other physical properties of nano-aluminum powder are determined by its preparation method. Different methods will have an impact on the performance of nano-aluminum powder.

 

The application of nano-aluminum powder

 

Efficient catalysts: Added aluminum nano-powders to the solid fuel rocket propellant can greatly improve the fuels combustion speed, combustion heat, improved the stability of combustion.

 

Metallic and non-metallic conductive coatings processing: Due to the Nano aluminum, copper, nickel has a high activation surface, in anaerobic conditions can be implemented coating below the powder melting point temperature. This technique can be applied to the production of microelectronic devices.

 

Activated sintering additives: Due to the surface area and surface atoms of nano-metal powder are accounted for large percentage, therefore, it has a higher energy state, in lower temperature will have strong sintering capacity, is a kind of efficient sintering additives. Nitride aluminum powder at about 300 will occur sintered behavior, will be produced an obvious sintering neck. Mixed with 5~10% of nano-aluminum powder in nitride aluminum powder, can be improved the thermal conductivity ceramic sintering process, improve sintered density and thermal conductivity. If it used as the substrate of integrated components, thermal conductivity will be increased 10 times, can be solved the integrated component of integration problem.

 

Production method of nano-aluminum powder

 

Put the aluminum into the crucible of hot metal evaporator, plasma transferred arc as heating source, melting the aluminum into liquid; the heating power of plasma transfer arc is 50~150KW; Begin to continuous feeding in the crucible of heat metal evaporator, feeding rate controlled at 0.3~5.0kg/h; the distilled aluminum vapor cooling by cooling gas and transported to particles controllers, aluminum vapor was continue cooling in particles controller, turned into solid state, form of nano-aluminum powder, particle size between 10~1000nm; nano-aluminum powder under the carrying of gas, after pass through the gas-solid separator, cooling to below 100, sediments to gas-solid separator collected in nano-aluminum powder collector, get the nano-aluminum powder, and the gas after cooled was recycle used or emptying.

 

Nano-aluminum powder is a new metal incendiary agent of energetic materials, has received significant attention in recent years because of its characteristics which common aluminum powder does not have. Nano-aluminum powder can significantly increase the propellant burn rate, specific impulse, reduce its characteristic signal. Whereas the loss activity nano-aluminum powder has opposite effect in energetic materials, so that systematic studies the activity of nano-aluminum powder and its active mechanism is particularly important and urgent.

 

Article Source:http://www.mhcmp.com

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