A METHOD OF MAKING WAX PATTERN DIE FOR MANUFACTURING HOLLOW BLADE NOZZLE OF GAS TURBINE BY INVESTMENT CASTING

摘要

Two cavity die is designed for producing a hollow blade nozzle. The suction side and pressure side of the nozzle are machined on left hand cavity (1) and right hand cavity (2) respectively. The root portion of the nozzle are provided on both the sides with additional blocks (3, 4, 5 and 6). Two cavities are formed with blocks (1, 3 and 4) and (2, 5 and 6) fixed and firmly tightens with the help of bolts to an angular plate (7) and angular plate (8) respectively. A slot with a defined curvature (10) is machined to accommodate curvature on blade profiles. On this curvature slot, the two cavities of the die are moved with angle plates (7 and 8) having a step to sit in the curvature slot. The ceramic core inside the die assembly is located at the root with a locating pin. Cylindrical locking pins (13, 14 and 15) are disposed to have accurate alignment and firm locking of the two cavities. Locating holes (16, 17 and 18) are machined on other cavity. These pins are located into the holes and form a good locking mechanism.