| 摘要 |
This process consists in applying the increasing isostatic gas pressure to the mould after it has been filled at a rate of increase such that the said pressure generates, rapidly and temporarily as a result of pressure drop through the sand, an excess pressure of the molten metal relative to the sand at the level of their interface, this excess pressure reaching a value lying between two limits and subsequently increasing as the said pressure increases, and then in maintaining the said pressure at a constant level until the part has completely solidified. This invention finds its application in the production of parts, in particular made from aluminium alloys, having, apart from an improved compactness, a surface which is free of blowholes and carbonaceous inclusions. |
