Production of atomized powder for glassy aluminum-based alloys

Abstract

A system and method for producing atomized powder for glassy aluminum-based alloys in an inert gas atmosphere. A melt chamber melts the alloy and it is atomized to form powder. The powder is deposited in at least one catch tank.

1 . A system for producing atomized powder for glassy or partially devitrified aluminum-based alloys, comprising:
 a melt chamber having a closed top, including an inert gas inlet for providing a positive pressure of inert gas therein;   a source of inert gas adapted to supply inert gas to the inlet;   a crucible for melting aluminum alloy therein, the crucible having an outlet for delivering molten aluminum alloy;   an atomization chamber positioned to receive molten aluminum alloy from the crucible and produce fine aluminum alloy powder from the molten alloy, including inert gas inlets for maintaining a positive pressure of inert gas;   inert gas inlets on the chamber for making powder; and   at least one catch tank for receiving powder produced in the atomization chamber while maintaining a positive pressure of inert gas.   
     
     
         2 . The system of  claim 1 , wherein a first catch tank is disposed for first receipt of the powder. 
     
     
         3 . The system of  claim 2 , wherein a first cyclone catch tank is disposed to receive powder downstream from the first catch tank. 
     
     
         4 . The system of  claim 3 , wherein a second cyclone catch tank is disposed to receive powder downstream from the first cyclone catch tank. 
     
     
         5 . The system of  claim 4 , wherein the first catch tank, the first cyclone tank and the second cyclone tank have isolation valves for closing access thereto. 
     
     
         6 . The system of  claim 1 , wherein the atomization chamber is maintained at a dew point of 35° F. to −110° F. (−37.2° C. to −78.9° C.). 
     
     
         7 . The system of  claim 1 , the atomization chamber has a gas composition of a mixture of helium and at least one inert gas wherein the ratio of helium to inert gas ranges from 100 in 3 /0 to 50 in 3 /50 in 3 . 
     
     
         8 . The system of  claim 1 , the crucible is adapted to heat the alloy to an upper temperature ranging from 1600° F. (871° C.) to 2200° F. (1204° C.). 
     
     
         9 . The system of  claim 1 , wherein the aluminum alloy is a devitrified glass-forming aluminum alloy having a nanometer-sized grain structure and nanometer-sized intermetallic phase or phases. 
     
     
         11 . A method for producing atomized powder for glassy aluminum-based alloys, comprising the steps of:
 providing a positive pressure of inert gas in a melt chamber having a closed top using an inert gas inlet;   supplying inert gas to the inlet from a source of inert gas;   melting an aluminum alloy in a crucible and delivering molten aluminum alloy out of the crucible;   receiving the molten aluminum alloy from the crucible into an atomization chamber and forming fine aluminum alloy powder from the molten alloy, while maintaining a positive pressure of inert gas in the atomization chamber; and   receiving powder produced in the atomization chamber in at least one catch tank while maintaining a positive pressure of inert gas therein.   
     
     
         12 . The method of  claim 11 , wherein the powder is transferred from the atomization chamber to a first catch tank. 
     
     
         13 . The method of  claim 12 , wherein a portion of the powder is transferred from the atomization chamber downstream from the first catch tank to a first cyclone catch tank. 
     
     
         14 . The method of  claim 13 , wherein an additional portion of the powder is transferred from the atomization chamber downstream from the first cyclone catch tank to a second cyclone catch tank, and wherein the first catch tank, the first cyclone tank and the second cyclone tank have isolation valves for closing access thereto. 
     
     
         15 . The method of  claim 11 , wherein the atomization chamber is maintained at a dew point of 35° F. to −110° F. (−37.2° C. to −78.9° C.). 
     
     
         16 . 
     
     
         17 . The method of  claim 11 , the atomization chamber has a gas composition of a mixture of helium and at least one inert gas wherein the ratio of helium to inert gas ranges from 100 in 3 /0 to 50 in 3 /50 in 3 . 
     
     
         18 . The method of  claim 11 , wherein the crucible is adapted to heat the alloy to an upper temperature ranging from 1600° F. (871° C.) to 2200° F. (1204° C.). 
     
     
         19 . The method of  claim 1 , wherein the aluminum alloy is a devitrified glass-forming aluminum alloy having a nanometer-sized grain structure and nanometer-sized intermetallic phase or phases. 
     
     
         20 . A method for producing atomized powder devitrified glass-forming aluminum alloys having a nanometer-sized grain structure and nanometer-sized intermetallic phase or phases, comprising the steps of:
 melting the alloy in a chamber having a positive pressure of inert gas;   melting an aluminum alloy in a crucible adapted to heat the alloy to an upper temperature ranging from 1600° F. (871° C.) to 2200° F. (1204° C.), wherein the atomization chamber is maintained at a dew point of 35° F. to −110° F. (−37.2° C. to −78.9° C.);   atomize the molten ally to a fine aluminum alloy powder; and   collecting the powder produced by atomization while maintaining a positive pressure of inert gas.