Method of and device for controlled quenching light metal castings in a liquid bath

Abstract

A method of controlled quenching of light metal castings in a liquid bath has castings in the liquid bath subjected, from below, at least temporarily, by a rising flow of gas bubbles. The gas bubbles are generated in situ in a uniformly distributed way at the base of the liquid bath.

What is claimed is:  
     
         1 . A method of controlling quenching light metal castings in a liquid bath comprising: 
 placing castings in the liquid bath;    subjecting the casting from below at least temporarily by a rising flow of gas bubbles; and    generating the gas bubble flow in situ at a base of the liquid bath.    
     
     
         2 . A method according to    claim 1   , further comprising uniformly distributing the gas bubbles at the base of the liquid bath.  
     
     
         3 . A method according to    claim 2   , further comprising positioning the castings at a desired distance above a generating zone of the gas bubbles.  
     
     
         4 . A method according to    claim 1   , further comprising pumping the liquid bath around in a cycle and re-cooling the liquid bath.  
     
     
         5 . A method according to    claim 1   , further comprising constantly feeding new liquid into the liquid bath at the base of the liquid bath and that excess quantities of liquid being constantly discharged from the liquid bath.  
     
     
         6 . A method according to    claim 1   , further comprising setting the flow of gas bubbles prior to the castings being fully immersed in the liquid bath.  
     
     
         7 . A method according to    claim 1   , further comprising terminating the flow of gas bubbles before the castings are removed from the liquid bath.  
     
     
         8 . A device for controlled quenching light metal castings in a liquid bath, comprising: 
 a tank to be filled with quenching liquid;    at least one inlet and one outlet coupled with said tank for ingress and egress of liquid;    a gas bubble generating device in said tank, said gas bubble generating device including a cover with a plurality of gas exit apertures positioned a distance from a base of said tank and at least one air supply chamber between said cover and the base of the tank.    
     
     
         9 . A device according to    claim 8   , wherein a carrying base for receiving castings is positioned above the cover.  
     
     
         10 . A device according to    claim 8   , wherein the cover includes a porous plate formed of an open metal foam, a porous ceramic material or sintered metal.  
     
     
         11 . A device according to    claim 8   , wherein the cover being a wire mesh element.  
     
     
         12 . A device according to    claim 8   , wherein a connector leads to the air supply chamber, said connector provided with a pressure control element for setting or controlling the flow of gas bubbles.