Specialized metallurgical processes – compositions for use therei – Processes – Producing or purifying free metal powder or producing or...
Patent
1996-07-22
1999-03-23
Wyszomierski, George
Specialized metallurgical processes, compositions for use therei
Processes
Producing or purifying free metal powder or producing or...
75371, 75722, B22F 924
Patent
active
058853219
ABSTRACT:
Fine aluminum powders are prepared by decomposing alane-adducts in organic solvents under an inert atmosphere to provide highly uniform particles selectably sized from about 65 nm to about 500 nm and believed particularly effective as fuels and additives, in pyrotechnics, and in energetic materials including composites, super thermite, and other explosives. Effective adduct species are trialkyl amines and tetramethylethylenediamine, ethers and other aromatic amines being believed effective. Effective production is obtained at atmospheric pressure and at temperatures as low as 50.degree. C. with xylene solvent. Increased production rate is achieved at higher temperatures. Toluene, dioxane, and tetramethylethylenediamine were also effective solvents. Aliphatic solvents and other aromatic and polar solvents are believed effective. Titanium catalyst was provided as a halide, amide, and alkoxide; and it is believed that the corresponding compounds of zirconium, hafnium, vanadium, niobium, and tantalum are effective as catalysts. Particle size was controlled by varying catalyst concentration and by varying the concentration of an adducting species, as by adding an amine to the solution or using an amine as the solvent. It is believed that particle size is controllable by varying the catalyst, concentration of the reactants, polarity of the solvent, reaction temperature, and the stage and rate at which the solution is brought to this temperature. The product powder is passivated in the reaction vessel by exposing the solution to air before product separation or by controlling the admission of air to the separated, dried powder.
REFERENCES:
patent: 3206326 (1965-09-01), Whaley et al.
patent: 3375129 (1968-03-01), Carley et al.
patent: 3462288 (1969-08-01), Schmidt et al.
patent: 3535108 (1970-10-01), Kobetz et al.
patent: 3552946 (1971-01-01), Brendel
patent: 3578436 (1971-05-01), Becker et al.
N.N. Korneev, N.N. Govorov, E.P. Bezukh, I.V. Schevchenko, and N.G. Gudko "Thermolysis of Dialkylhydridioaluminums in Presence of Complex Formers"; translated from Zhurnal Obshchei Khimii, vol. 55, No. 8, pp. 1762-1767, Aug. 1985.
W.L.Gladfelter, D.C. Boyd, K.F. Jensen; "Trimethylamine Complexes of Alane as Precursors for the Low-Pressure Chemical Vapor Deposition of Aluminum"; Chemical of Materials 1989, 1,339-343.
ASM Handbook, vol. 7, Powder Metallurgy, "Explosivity and Pyrophoricity of Metal Powders", pp. 194-199, ASM, 1984.
Higa Kelvin T.
Hollins Richard A.
Johnson Curtis E.
Bokar Gregory M.
Church Stephen J.
Kalmbaugh David S.
The United States of America as represented by the Secretary of
Wyszomierski George
LandOfFree
Preparation of fine aluminum powders by solution methods does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Preparation of fine aluminum powders by solution methods, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Preparation of fine aluminum powders by solution methods will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2121201