| 摘要 |
To minimise temperature drop of a preheated blank (12) of inferior formability, such as titanium alloy, beryllium alloy or managing steel, during forming operation and thereby to relieve difficulty of press forming, at least one side of the blank (12) is covered with a layer (15) of a compressible heat-insulating material such as asbestos or ceramic fibre such that a punch (22) for press forming does not come into direct contact with the heated blank (12). The blank (12) and the heat-insulating layer (15) are preheated substantially to the same extent. Preferably the blank (12) is sandwiched between two plates (16, 18) of a metal having a better formability, and at least one side of the resultant lamination is covered with the heat- insulating layer (15). <IMAGE> |
