Method of making brazed honeycomb structures

Claim 1

THE METHOD OF MAKING A METAL HONEYCOMB STRUCTURE, SAID STRUCTURE COMPRISING A METAL TOP SKIN AND A METAL BOTTOM SKIN SPACED APART FROMA CONNECTED TO EACH OTHER BY A METAL HONEYCOMB CORE, WHICH COMPRISES: (A) ASSEMBLING A COMPOSITE HONEYCOMB SANDWICH CONSISTING ESSENTIALLY OF THE METAL TO P SKIN, A LAYER OF A SELFFLUXING FIRST BRAZING ALLOY IN CONTACT WITH SAID TOP SKIN, A LAYER OF A SECOND BRAZING ALLOY IN CONTACT WITH SAID FIRST BRAZING ALLOY, THE METAL HONEYCOMB CORE IN CONTACT WITH SAID SECOND BRAZING ALLOY, A LAYER OF THE SECOND BRAZING ALLOY IN CONTACT WITH SAID HONEYCOMB CORE A LAYER OF THE FIRST BRAZING ALLOY IN CONTACT WITH SAID SECOND BRAZING ALLOY, AND THE METAL BOTTOM SKIN OF THE HONEYCOMB STRUCTURE IN CONTACT WITH SAID FIRST BRAZING ALLOY, SAID SECOND BRAZING ALLOY HAVING A FLOW TEMPERATURE AT LEAST 50*F. HIGHER THAN THE FLOW TEMPERATURE OF SAID FIRST BRAZING ALLOY AND HAVING A FLOW TEMPERATURE AT SAID FIRST BRAZING ALLOY AND SAID SECOND BRAZING ALLOY WILL READILY ALLOY AT A TEMPERATURE INTERMEDIATE THE FLOW TEMPERATURES OF SAID FIRST AND SECOND BRAZING ALLOYS TO FORM A THIRD BRAZING ALLOY HAVING A FLOW TEMPERATURE INTERMEDIATE THE FLOW TEMPERATURE OF SAID FIRST AND SECOND BRAZING ALLOYS, AND (B) HEATING THE COMPOSITE HONEYCOMB SANDWICH TO A BRAZING TEMPERATURE AT LEAST AS HIGH AS THE FLOW TEMPERATURE OF THE FIRST BRAZING ALLOY AND THE FLUID BRAZING ALLOY BUT BELOW THE FLOW TEMPERATURE OF THE SECOND BRAZING ALLOY FOR A LENGTH OF TIME SUFFICIENT TO CAUSE SAID LAYERS OF SAID FIRST ALLOY TO THOROUGHLY WET THE ADJACENT SURFACE OF SAID AND TO FORM SAID THIRD BRAZING ALLOY AND TO BRAZE THE HONEYCOMB SANDWICH TOGETHER, THE RESULTING BRAZED HONEYCOMB STRUCTURE BEING CHARACTERIZED BY A RATIO BETWEEN THE AVERAGE SIZE OF THE TOP FILLET AND THE AVERAGE SIZE OF THE BOTTOM FILLET OF LESS THAN 1:3.

Claim 2

THE METHOD OF MAKING A METAL HONEYCOMB STRUCTURE, SAID STRUCTURE COMPRISING A METAL TOP SKIN AND A METAL BOTTOM SKIN SPACED APART FROMA CONNECTED TO EACH OTHER BY A METAL HONEYCOMB CORE, WHICH COMPRISES: (A) ASSEMBLING A COMPOSITE HONEYCOMB SANDWICH CONSISTING ESSENTIALLY OF THE METAL TO P SKIN, A LAYER OF A SELFFLUXING FIRST BRAZING ALLOY IN CONTACT WITH SAID TOP SKIN, A LAYER OF A SECOND BRAZING ALLOY IN CONTACT WITH SAID FIRST BRAZING ALLOY, THE METAL HONEYCOMB CORE IN CONTACT WITH SAID SECOND BRAZING ALLOY, A LAYER OF THE SECOND BRAZING ALLOY IN CONTACT WITH SAID HONEYCOMB CORE A LAYER OF THE FIRST BRAZING ALLOY IN CONTACT WITH SAID SECOND BRAZING ALLOY, AND THE METAL BOTTOM SKIN OF THE HONEYCOMB STRUCTURE IN CONTACT WITH SAID FIRST BRAZING ALLOY, SAID SECOND BRAZING ALLOY HAVING A FLOW TEMPERATURE AT LEAST 50*F. HIGHER THAN THE FLOW TEMPERATURE OF SAID FIRST BRAZING ALLOY AND HAVING A FLOW TEMPERATURE AT SAID FIRST BRAZING ALLOY AND SAID SECOND BRAZING ALLOY WILL READILY ALLOY AT A TEMPERATURE INTERMEDIATE THE FLOW TEMPERATURES OF SAID FIRST AND SECOND BRAZING ALLOYS TO FORM A THIRD BRAZING ALLOY HAVING A FLOW TEMPERATURE INTERMEDIATE THE FLOW TEMPERATURE OF SAID FIRST AND SECOND BRAZING ALLOYS, AND (B) HEATING THE COMPOSITE HONEYCOMB SANDWICH TO A BRAZING TEMPERATURE AT LEAST AS HIGH AS THE FLOW TEMPERATURE OF THE FIRST BRAZING ALLOY AND THE FLUID BRAZING ALLOY BUT BELOW THE FLOW TEMPERATURE OF THE SECOND BRAZING ALLOY FOR A LENGTH OF TIME SUFFICIENT TO CAUSE SAID LAYERS OF SAID FIRST ALLOY TO THOROUGHLY WET THE ADJACENT SURFACE OF SAID AND TO FORM SAID THIRD BRAZING ALLOY AND TO BRAZE THE HONEYCOMB SANDWICH TOGETHER, THE RESULTING BRAZED HONEYCOMB STRUCTURE BEING CHARACTERIZED BY A RATIO BETWEEN THE AVERAGE SIZE OF THE TOP FILLET AND THE AVERAGE SIZE OF THE BOTTOM FILLET OF LESS THAN 1:3.