Method of making precursor hollow castings for tube manufacture

Abstract

A tubular formation technique utilizing centrifugal casting incorporating a moveable launder system to deliver molten alloy along an extended length within a centrifugal caster to form a hollow tubular precursor of extended length. The technique is adaptable to all alloy systems but may be particularly suited for so called “hard alloys” that are susceptible to substantial work hardening or are difficult to extrude.

1 . A casting system comprising:
 a centrifugal caster having an interior and a material acceptance opening; and   an elongate moveable launder adapted for insertion through the material acceptance opening and into the interior of the caster for delivery of molten metal to positions along the interior of the caster spaced away from the material acceptance opening.   
     
     
         2 . The casting system of  claim 1 , wherein the elongate moveable launder is moveable in reciprocating relation relative to the caster. 
     
     
         3 . The casting system of  claim 2 , wherein the elongate moveable launder is mounted on rails. 
     
     
         4 . The casting system of  claim 1 , wherein the molten metal is selected from at least one of the group consisting of: aluminum, aluminum alloys, magnesium, magnesium alloys, titanium and titanium alloys, copper and copper alloys, and refractory metals and their alloys. 
     
     
         5 . Billets formed by the casting system of  claim 1 . 
     
     
         6 . The casting system of  claim 1 , further comprising a flow forming apparatus adapted to process billets from the caster. 
     
     
         7 . A method of centrifugally casting a tubular billet, the method comprising the steps of:
 providing a centrifugal caster having an interior and a material acceptance opening;   providing an elongate moveable launder adapted for reciprocating insertion and withdrawal through the material acceptance opening and into the interior of the caster for delivery of molten metal to positions along the interior of the caster spaced away from the material acceptance opening;   inserting a distal portion of the launder into the interior of the caster;   delivering a quantity of molten metal along the launder from a position outside the caster to the interior of the caster for deposit at locations spaced away from the material acceptance opening; and   expelling hollow substantially tubular billets from the caster.   
     
     
         8 . The method as recited in  claim 7 , wherein the molten metal is deposited as the launder is moved in reciprocating relation to the caster such that the molten metal is deposited in layers along the length of the caster, and where the individual layers can be a different metal or alloy. 
     
     
         9 . The method as recited in  claim 7 , wherein the elongate moveable launder is mounted on rails. 
     
     
         10 . The method as recited in  claim 7 , wherein the molten metal is selected from at least one of the group consisting of: aluminum, aluminum alloys, magnesium, magnesium alloys, titanium and titanium alloys, copper and copper alloys, and refractory metals and their alloys. 
     
     
         11 . A method of centrifugally casting and flow forming a tubular billet, the method comprising the steps of:
 providing a centrifugal caster having an interior and a material acceptance opening;   providing an elongate moveable launder adapted for reciprocating insertion and withdrawal through the material acceptance opening and into the interior of the caster for delivery of molten metal to positions along the interior of the caster spaced away from the material acceptance opening;   inserting a distal portion of the launder into the interior of the caster;   delivering a quantity of molten metal along the launder from a position outside the caster to the interior of the caster for deposit at locations spaced away from the material acceptance opening;   expelling hollow substantially tubular billets from the caster; and   delivering the tubular billets to a wall thinning flow forming apparatus adapted to process the billets from the caster.   
     
     
         12 . The method as recited in  claim 11 , wherein the molten metal is deposited as the launder is moved in reciprocating relation to the caster such that the molten metal is deposited in layers along the length of the caster, and where the individual layers can be a different metal or alloy. 
     
     
         13 . The method as recited in  claim 11 , wherein the elongate moveable launder is mounted on rails. 
     
     
         14 . The method as recited in  claim 11 , wherein the molten metal is selected from at least one of the group consisting of: aluminum, aluminum alloys, magnesium, magnesium alloys, titanium and titanium alloys, copper and copper alloys, and refractory metals and their alloys.