Inert gas shielding for rapid solidification apparatus

Abstract

A rapid solidification apparatus is provided. The rapid solidification apparatus includes a movable chill body defining a quench surface, a molten material nozzle for directing one or more streams of molten material towards the quench surface and a source of inert gas. The source of inert gas is configured to provide a conical shield of pressurized inert gas around the one or more streams of molten material. The conical shield extends from the molten material nozzle towards the quench surface with focal point of the conical shield at or proximate the quench surface.

What is claimed is: 
     
         1 . A rapid solidification apparatus comprising:
 a movable chill body defining a quench surface;   a molten material nozzle for directing one or more streams of molten material towards the quench surface; and   a source of inert gas configured to provide a conical shield of pressurized inert gas around the one or more streams of molten material, the conical shield extending from the molten material nozzle towards the quench surface with focal point of the conical shield at or proximate the quench surface.   
     
     
         2 . A rapid solidification apparatus as claimed in  claim 1  wherein the source of inert gas is a plurality of gas nozzles. 
     
     
         3 . A rapid solidification apparatus as claimed in  claim 1  wherein the source of inert gas is attached to the molten material nozzle. 
     
     
         4 . A rapid solidification apparatus as claimed in  claim 1  wherein the source of inert gas is configured to direct pressurized inert gas towards the molten material nozzle and the chill body. 
     
     
         5 . A rapid solidification apparatus as claimed in  claim 1  wherein the rapid solidification apparatus includes a heating device. 
     
     
         6 . A rapid solidification apparatus as claimed in  claim 1  wherein the source of inert gas is an angled nozzle ring. 
     
     
         7 . A rapid solidification apparatus as claimed in  claim 1  wherein the focal point of the conical shield is upstream of the point of contact between the molten material and the chill body. 
     
     
         8 . A rapid solidification apparatus as claimed in  claim 1  further comprising a second source of inert gas configured to provide a second conical shield of inert gas surrounding the conical shield. 
     
     
         9 . A rapid solidification apparatus as claimed in  claim 8  wherein the second conical shield extends from the molten material nozzle towards the chill body with focal point of the second conical shield at or proximate the chill body and upstream of the point of contact between the molten material and the chill body. 
     
     
         10 . A rapid solidification apparatus as claimed in  claim 9  wherein the focal point of the conical shield is at the stream of molten material. 
     
     
         11 . A rapid solidification apparatus as claimed in  claim 1  wherein the movable chill body is a chill roll. 
     
     
         12 . A rapid solidification apparatus as claimed in  claim 1  wherein the pressure of the pressurized inert gas is greater than or equal to 30 psi. 
     
     
         13 . A method of rapidly solidifying a molten material comprising:
 directing one or more streams of molten material from a source of molten material towards a moving chill body defining a quench surface; and   providing a conical shield of pressurized inert gas around the one or more streams of molten material, the conical shield extending from the source of molten material towards the quench surface with focal point of the conical shield at or proximate the quench surface.   
     
     
         14 . The method of  claim 13  comprising pressurizing the pressurized inert gas to greater than or equal to 30 psi. 
     
     
         15 . The method of  claim 13  comprising directing pressurized inert gas towards the source of molten material and the chill body. 
     
     
         16 . The method of  claim 13  wherein the focal point of the conical shield is upstream of the point of contact between the molten material and the chill body. 
     
     
         17 . The method of  claim 13  further comprising providing a second conical shield of inert gas that surrounds the conical shield. 
     
     
         18 . The method of  claim 17  further comprising pressurizing the inert gas of the second conical shield. 
     
     
         19 . The method of  claim 17  wherein the second conical shield extends from the source of molten material towards the chill body with the focal point of the second conical shield at or proximate the chill body and upstream of the point of contact between the molten material and the chill body. 
     
     
         20 . The method of  claim 19  wherein the focal point of the conical shield is at the stream of molten material.