Granted Patent B2

US 10,307,856 · App. 14/938,549 · Granted Jun 4, 2019

Abstract

Claims (30)

1. A method of manufacturing a honeycomb core, the method comprising the steps of:

applying a pattern of strips of a stop-off material to surfaces of a plurality of sheets of metal at locations where diffusion bonding is not desired, the step of applying the pattern of strips including the sub-steps of:

applying a first strip having at least one of a first width, spacing, shape, and size; and

applying a second strip having at least one of a second width, spacing, shape, and size different than the first width, spacing, shape, or size of the first strip so that the pattern of strips includes at least two different widths, spacings, shapes, or sizes;

stacking the sheets of metal together in a sequence for forming the honeycomb core;

pressing the sheets of metal together between two press plates comprising conductive material;

applying electric current to the conductive material of the press plates, such that current flows through a thickness of the sheets of metal and such that the sheets of metal are diffusion bonded to each other at locations absent the stop-off material; and

expanding the sheets of metal into the honeycomb core so that the at least two different widths, spacings, shapes, or sizes effects at least one of selective contouring of the honeycomb core and at least two different densities of honeycomb core cells.

2. The method of claim 1 , wherein the step of expanding the sheets of metal into the honeycomb core comprises pulling outer-most ones of the sheets of metal in opposite directions away from each other.

3. The method of claim 1 , wherein the step of applying electric current is performed in ambient air or with the sheets of metal substantially surrounded by a cover of a shielding gas.

4. The method of claim 1 , wherein the applying of electric current is performed for less than thirty minutes.

5. The method of claim 1 , wherein the pressure applied via the two press plates pressing the sheets of metal together is between 5,000 and 10,000 PSI.

6. The method of claim 1 , wherein the applying step comprises printing a brazing stop-off compound or ceramic stop-off paint onto at least one side of each of the sheets of metal.

7. The method of claim 1 , wherein the pattern of spaced apart strips of the stop-off material is alternated or inverted for each successive one of the sheets of metal stacked together.

8. The method of claim 1 , further comprising a step of removing material from the diffusion bonded sheets of metal so as to modify the diffusion bonded sheets of metal into a desired configuration prior to the step of expanding the sheets of metal into the honeycomb core.

9. A method of manufacturing a honeycomb core, the method comprising the steps of:

printing a pattern of spaced apart strips of a stop-off material to surfaces of a plurality of sheets of metal at locations where diffusion bonding is not desired, wherein the printing step includes the sub-steps of:

printing a first strip having at least one of a first width, spacing, shape, and size; and

printing a second strip having at least one of a second width, spacing, shape, and size different than the first width, spacing, shape, or size of the first strip so that the pattern of strips includes at least two different widths, spacings, shapes, or sizes;

stacking the sheets of metal together in a sequence for forming the honeycomb core;

pressing the sheets of metal together between two press plates comprising conductive material;

applying electric current to the conductive material of the press plates, such that current flows through a thickness of the sheets of metal and such that the sheets of metal are diffusion bonded to each other at locations absent the stop-off material; and

expanding the sheets of metal into the honeycomb core after the locations absent the stop-off material are diffusion bonded with adjacent ones of the sheets of metal so that the at least two different widths, spacings, shapes, or sizes effects at least one of selective contouring of the honeycomb core and at least two different densities of honeycomb core cells.

10. The method of claim 9 , wherein the step of expanding the sheets of metal into the honeycomb core comprises pulling outer-most ones of the sheets of metal in opposite directions away from each other.

11. The method of claim 9 , wherein the step of applying electric current is performed in ambient air or with the sheets of metal substantially surrounded by a cover of a shielding gas.

12. The method of claim 9 , wherein the applying of electric current is performed for less than thirty minutes.

13. The method of claim 9 , wherein the pressure applied via the two press plates pressing the sheets of metal together is between 5,000 and 10,000 PSI.

14. The method of claim 9 , wherein the printing step comprises printing a brazing stop-off compound or ceramic stop-off paint onto at least one side of each of the sheets of metal.

15. The method of claim 9 , wherein the pattern of spaced apart strips of the stop-off material is substantially alternated or inverted for successive ones of the sheets of metal stacked together.

16. The method of claim 9 , further comprising a step of removing material from the diffusion bonded sheets of metal so as to modify the diffusion bonded sheets of metal into a desired configuration prior to the step of expanding the sheets of metal into the honeycomb core.

Assignments (12)