Corrosion resistant charge air cooler and method of making same

Abstract

A corrosion-resistant heat exchanger for use in cooling a mixture of exhaust gas and charged air is provided comprising an air inlet chamber, an air outlet chamber, and a plurality of flat tubes through which the mixture passes and is cooled by ambient air. The flat tubes include turbulators to promote cooling of the exhaust gas/air mixture, and the turbulators are formed from a first aluminum alloy that is cladded by a second aluminum alloy, which combination of alloys create a sacrificial “brown band” layer upon brazing. In a highly preferred embodiment, both the tubes and the turbulators are formed of the same material.

1 . An air-to-air heat exchanger for use in a motor vehicle comprising a charge air inlet chamber, a charge air outlet chamber and a plurality of flat tubes, wherein the flat tubes include a plurality of turbulators comprised of a first cladding, a core and a second cladding, and wherein the first cladding and core combine during brazing to create a sacrificial layer against corrosion.  
   
   
       2 . The air-to-air heat exchanger of  claim 1 , wherein the first cladding comprises no more than fifteen percent (15%) of the thickness of the core.  
   
   
       3 . The air-to-air heat exchanger of  claim 1 , wherein the first cladding comprises no more than five percent (5%) of the thickness of the core.  
   
   
       4 . The air-to-air heat exchanger of  claim 1 , wherein the first cladding comprises no more than fifteen percent (15%) of the thickness of the core and the second cladding comprises no more than fifteen percent (15%) of the thickness of the core.  
   
   
       5 . The air-to-air heat exchanger of  claim 1 , wherein the first cladding and the second cladding is comprised of a 4000 series aluminum alloy.  
   
   
       6 . The air-to-air heat exchanger of  claim 5 , wherein the first cladding is comprised of an alloy selected from the group consisting of 4004, 4045, 4047, 4104 or 4545 aluminum alloys.  
   
   
       7 . The air-to-air heat exchanger of  claim 5 , wherein the cladding is comprised of a 4045 aluminum alloy and the core is comprised of a 3003 aluminum alloy.  
   
   
       8 . The air-to-air heat exchanger of  claim 1 , wherein the turbulators are generally U-shaped.  
   
   
       9 . A heat exchanger for use in a motor vehicle comprising a inlet chamber, an outlet chamber and a plurality of tubes defining a fluid path, wherein the flat tubes include a plurality of turbulators comprised of a cladding and a core, and wherein the cladding and core combine during brazing to create a sacrificial layer against corrosion.  
   
   
       10 . The air-to-air heat exchanger of  claim 9 , wherein the first cladding comprises no more than fifteen percent (5%) of the thickness of the core.  
   
   
       11 . The air-to-air heat exchanger of  claim 9 , wherein the first cladding is attached to the core in a direction transverse to the fluid path.  
   
   
       12 . A method for manufacturing a component for use in a motor vehicle comprising the steps of: 
 rolling a cladding of a first aluminum alloy composition onto a core of a second aluminum alloy composition to define a metal composition for use as a turbulator within a heat exchanger;    assembling a plurality of turbulator components formed from the metal composition within a plurality of flat tubes;    brazing the assembled turbulators to the flat tubes to form a sacrificial layer.    
   
   
       13 . The method of  claim 12 , wherein the cladding comprises no more than fifteen percent (15%) of the thickness of the core.  
   
   
       14 . The method of  claim 12 , wherein the cladding comprises no more than five percent (5%) of the thickness of the core.  
   
   
       15 . The method of  claim 12 , wherein the first aluminum alloy is a 4000 series aluminum alloy.  
   
   
       16 . The method of  claim 15 , wherein the second aluminum alloy is comprised of an alloy selected from the group consisting of 4004, 4045, 4047, 4104 or 4545 aluminum alloys.  
   
   
       17 . The method of  claim 15 , wherein the cladding is comprised of a 4045 aluminum alloy and the core is comprised of a 3003 aluminum alloy.  
   
   
       18 . The method of  claim 12 , further comprising the step of rolling a second cladding of a first aluminum alloy composition onto the core of the metal composition prior to the step of brazing.