| 摘要 |
A method is described for eliminating internal pores in superplastically shaped pieces. A blank 6 of material which can be superplastically shaped is held against a shaping surface 16 in a mould 2, 4. The blank is heated to a temperature for superplastic shaping and a pressure 18, 20 is applied to both sides of the blank. This pressure is sufficient to prevent the formation of pores. The pressure 18 at the side of the blank situated furthest away from the shaping surface 16 is then increased for superplastic shaping of the material against the shaping surface 16. According to another embodiment, the pressure is applied after the blank has been shaped either in that the shaping pressure 38 is maintained for pressing of the material between the shaping pressure and the reaction 40 of the mould, or by applying a fluid pressure to both sides of the blank, whereby pores are removed by plastic deformation and diffusion. <IMAGE> |
