| 摘要 |
Disclosed is a method for manufacturing a silicon nitride extrusion die comprising: a step (a) of manufacturing raw materials through a spray dry process by adding 80 wt% of silicon nitride (Si_3N_4) powder, 9 wt% of yttria (Y_2O_3) and 11 wt% of aluminum nitride (AIN); a step (b) of manufacturing a press molded product by pressing a mold after the raw materials are charged in the mold; a step (c) of pre-sintering the molded product at 600-800°C for 15 hours; a step (d) of processing the pre-sintered molded product to the shape of a tip; a step (e) of pressure-sintering the processed tip at 1,740°C for 2-3 hours with the 100-200 atmospheric pressure of argon (Ar); a step (f) of completing a silicon nitride tip by processing the outer diameter, the inner diameter, and the thickness of the tip passed the step (e) using a diamond grindstone; a step (g) of preparing a metal case having the outer diameter 0.1% smaller than the outer diameter of the silicon nitride tip by rough-machining hot tool steel (skd61) having the HRC 48-52 of a thermal treatment hardness; and a step (h) of shrink-fitting the completed silicon nitride tip in the metal case heated at 400-450°C. [Reference numerals] (AA) Metal case machining process; (BB) Shrink fitting process; (S1) Raw material manufacturing process; (S2) Molded product manufacturing process; (S3) Pre-sintering process; (S4) Tip forming process; (S5) Pressure sintering process; (S6) Silicon nitride tip completing process |
