Ceramic core spacer blocks for high temperature preheat cycles

Abstract

A spacer member in a furnace including an aluminum tube containing a ceramic material. The ceramic material provides high compressive strength and the composite product resists high temperature creep.

1 . A spacer member for supporting an aluminum alloy product subjected to a heat treatment, said spacer member comprising a metal housing surrounding a ceramic core, said spacer member having a surface configured to support a portion of an aluminum alloy ingot in a furnace.  
   
   
       2 . The spacer member of  claim 1  wherein said metal housing comprises a metal selected form the group consisting of an aluminum alloy, steel, a nickel alloy, a cobalt alloy and a titanium alloy.  
   
   
       3 . The spacer member of  claim 1  wherein said metal housing comprises a metal tube.  
   
   
       4 . The spacer member of  claim 3  wherein said metal tube is an extruded tube.  
   
   
       5 . The spacer member of  claim 3  wherein said metal tube is a welded tube.  
   
   
       6 . The spacer member of  claim 3  further comprising a pair of end caps.  
   
   
       7 . The spacer member of  claim 6  wherein said end caps are integrally formed with said tube.  
   
   
       8 . The spacer member of  claim 6  wherein said end caps are fixed to opposing ends of said tube.  
   
   
       9 . The spacer member of  claim 1  wherein said housing comprises an aluminum alloy having a solidus temperature of over about 1180° F.  
   
   
       10 . The spacer member of  claim 9  wherein said housing comprises an Aluminum Association alloy selected from the group consisting of 7072, 3105, 3003, 1350, 1145, 1060, 1050, and 1199.  
   
   
       11 . The spacer member of  claim 1  wherein said ceramic core comprises a material selected from the group consisting of a calcium aluminate, an aluminum silicate, a magnesium silicate, silica, a high alumina cement, a low cement castable, a silica fume low-cement castable, an ultralow-cement castable, a cement-free castable, an alumina-magnesia spinel, a basic low-cement castable, a gel-bond castable and a plastic refractory.  
   
   
       12 . The spacer member of  claim 1  wherein said ceramic core has a maximum density of about 125 lbs/ft 3 .  
   
   
       13 . The spacer member of  claim 1  wherein said ceramic core has a cold crushing strength of at least about 2000 psi.  
   
   
       14 . The spacer member of  claim 1  further comprising a coating on said surface of said housing, said coating being configured to minimize sticking of an aluminum product to said spacer member during a heat treatment.  
   
   
       15 . The spacer member of  claim 14  wherein said coating comprises a material selected from the group consisting of nickel and alloys thereof, molybdenum and alloys thereof, and boron containing compounds.  
   
   
       16 . The spacer member of  claim 1  wherein said surface has an Ra roughness of about 10 to about 10,000 microinches.  
   
   
       17 . The spacer member of  claim 3  wherein said metal tube has a width of up to about 3 inches.  
   
   
       18 . The spacer member of  claim 1  wherein said spacer member weighs a maximum of about 5 pounds.  
   
   
       19 . The spacer member of  claim 1  further comprising a strengthening member within said core.  
   
   
       20 . The spacer member of  claim 19  wherein said strengthening member comprises a plurality of metal fibers.  
   
   
       21 . The spacer member of  claim 19  wherein said strengthening member comprises a mesh sheet.  
   
   
       22 . The spacer member of  claim 19  wherein said strengthening member comprises a mesh tubular body.  
   
   
       23 . A method of making a spacer member for supporting an aluminum alloy product subjected to a heat treatment, said method comprising the steps of: 
 a) providing a metal housing;    b) filling the metal housing with a ceramic material; and    c) enclosing the ceramic material within the housing.    
   
   
       24 . The method of  claim 23  wherein said metal housing comprises a metal selected form the group consisting of an aluminum alloy, steel, a nickel alloy, a cobalt alloy and a titanium alloy.  
   
   
       25 . The method of  claim 23  wherein step a) comprises extruding a metal tube.  
   
   
       26 . The method of  claim 24  wherein said metal tube comprises an aluminum alloy having a solidus temperature of over about 1180° F.  
   
   
       27 . The method of  claim 23  wherein step a) comprises shaping a metal sheet into a tube shape and welding together opposite edges of the sheet to form a tube.  
   
   
       28 . The method of  claim 23  wherein step a) comprises providing a metal tube and capping one end of the tube.  
   
   
       29 . The method of  claim 28  wherein step c) comprises capping the other end of the tube.  
   
   
       30 . The method of  claim 23  wherein step b) comprises placing a curable ceramic material into the metal housing and curing the ceramic material.  
   
   
       31 . The method of  claim 30  wherein the ceramic material comprises a composition selected from the group consisting of a calcium aluminate, an aluminum silicate, a magnesium silicate, silica, a high alumina cement, a low cement castable, a silica fume low-cement castable, an ultralow-cement castable, a cement-free castable, an alumina-magnesia spinel, a basic low-cement castable, a gel-bond castable and a plastic refractory.  
   
   
       32 . The method of  claim 23  further comprising applying to an exterior surface of the metal housing a nonstick coating for preventing sticking of a heat treated aluminum product to the spacer member.  
   
   
       33 . The method of  claim 32  wherein the coating comprises a material selected from the group consisting of nickel and alloys thereof, molybdenum and alloys thereof, and boron containing compounds.  
   
   
       34 . The method of  claim 23  further comprising placing a strengthening member into said curable ceramic material such that the cured ceramic material fixes the strengthening member in place.