Inventors:
George B. Meginnis - Indianapolis IN
Assignee:
General Motors Corporation - Detroit MI
International Classification:
B23K 3102
Abstract:
A method for manufacturing a composite sheet of material having a controlled porous characteristic and made up of two or more metal lamina bonded together, including the steps of forming first and second sheets of porous material with a first and second array of openings therein offset with respect to one another; stacking the first and second sheets together to form a peripheral joint line therebetween having end edges indexed to align the first and second array of openings to form a coolant flow pattern through the stacked sheets; welding indexed end edges to fixedly connect the first and second sheets together; stretch-forming the stacked sheets by bending them under tension across a predetermined curvature on a form die to cause the first and second sheets to exceed their yield point to effect an intimate fit across juxtaposed surfaces thereon; thereafter further bending and restraining the welded end edges of the first and second sheets to produce a bond pressure between the sheets at the juxtaposed surfaces thereon and thereafter subjecting restrained and mechanically pressurized juxtaposed surfaces between the first and second sheets to an elevated bonding temperature for a predetermined period of time to produce a diffusion bonded metal joint between the stacked sheets.