| 摘要 |
A method of forming sheets of superplastically formable material into a three dimensional article, the sheets being joined together along diffusion bonds to form discrete cells, at least one gas path being provided through the bond between cells. The sheets are heated to a temperature at which they exhibit superplastic properties and a gas injected between the sheets to expand the cells, the gas paths allowing the injected gas to pass from cell to cell. The edges of the gas paths are locally heated to change the microstructure of the sheets in the edge areas, which reduces the flow resistance of the edges under superplastic forming conditions and thereby reduces the propensity of the diffusion bonds bordering the gas transfer holes to peel apart under the forces of the inert gas exerted on the sheets at the gas transfer paths. |
