| 摘要 |
1,212,819. Casting processes. PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd. 22 Sept., 1969 [25 Sept., 19681, No. 46538/69. Heading B3F. A method of making a perforated metal plate of aluminium or an alloy between aluminium and magnesium comprises forcing the molten metal under pressure into a cavity 5 in which a matrix of metal cores corresponding to the apertures to be formed is situated and, after solidification, withdrawing the cores 3 from the casting. The cores 3 are attached to a base-plate 2 and extend through apertures in an intermediate plate 4 into the cavity 3. The cores are removed from the casting by moving the plate 4 and upper plate 6 upwards by means of pressure rods 10. The cores may be made of a ferrochromium alloy and are preheated to about 100‹ C. |
