METHOD OF PRODUCING LIGHT-WEIGHT SILICON PLATES AND BUILT-UP MOULD FOR EMBODYING SAME Russian patent published in 1995 - IPC

FIELD: foundry practice. SUBSTANCE: the mould is built-up from graphite of different grades. A novel feature of the mould is that solid cores are made from graphite with a coefficient of thermal expansion exceeding that of the silicon by a factor of 1.7 to 2.1. The cores are spaced apart by a distance which is between 0.07 and 0.2 times their height. The mould temperature before pouring is maintained at 1400 - 0.1 1400 - 0,1/αd where α is the coefficient of thermal expansion of the core material and d is the cross sectional area of the core in square mm. EFFECT: improved quality of castings. 4 cl, 2 dwg