| 摘要 |
PURPOSE:To improve the mechanical strength of a glass ceramic cast by heat treatment by sufficiently relieving the thermal stress generated in the cast in a short time. CONSTITUTION:The ingot of a glass ceramic is kept at 1450 deg.C for 4min in a platinum resistance heating furnace, the molten glass is introduced into a casting mold kept at 575 deg.C and centrifugally cast at 1200r.p.m. for 1min. The cast is let stand in a heating furnace held at 575 deg.C, and then the cast is heated to 750 deg.C in 1hr, held at 750 deg.C for 2hr, further heated to 900 deg.C at the rate of 4 deg.C/min and crystallized. The cast is then allowed to cool to room temp. |
