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近代航空工业生产的喷气发动机,为了提高涡轮前进口温度,单纯的依靠提高涡轮叶片材料的耐热性能已经满足不了近代高性能发动机的要求,因为材料本身耐热性能的潜力已经不大。目前,空冷技术已在国内外的涡轮叶片和导向叶片上得到了广泛的采用,它可以使涡轮前进口温度至少提高120℃以上,从而提高了发动机的推力。采用石英玻璃型芯(以下简称型芯)形成的精铸涡轮叶片孔型就是一种新的冷却方式。由于型芯做成复杂异型孔形较困难,一般采用断面为圆形或椭圆形较多,圆形型芯直径达φ0.8～φ1.0毫米已经在国内用于批生产。在精铸涡轮叶片批生产中,直径为中φ1.0毫米的型芯往往在型壳和铸件中产生断芯,断芯位置在靠近转角R处。断芯与型芯材料、模具结构、模料、制壳工艺、铸件的凝固等因素有关系,经过试验和多年批生产实践已经掌握了断芯规律和解决方法,从而稳定了批生产质量,型壳断芯率由试制初期的70％以上降到10％以下,铸件中的断芯已基本消除。
In recent years, the jet engine manufactured by the aviation industry can not meet the requirements of modern high-performance engines simply by increasing the heat resistance of turbine blade materials in order to increase the inlet temperature of the turbine. At present, air-cooling technology has been widely used in turbine blades and guide vanes both at home and abroad. It can increase the temperature of the inlet of the turbine by at least 120 ℃ and increase the thrust of the engine. The use of quartz glass core (hereinafter referred to as core) to form a fine cast turbine blade hole is a new cooling method. As the core made of complex shaped hole more difficult, the general use of cross-section is more round or oval, round core diameter φ0.8 ~ φ1.0 mm has been used in the country for batch production. In the production of fine cast turbine blades, a core of 1.0 mm in diameter tends to generate a broken core in the shell and castings, with the broken core located near the corner R. Broken core and core material, mold structure, mold material, shell making process, solidification of castings and other factors have been tested and years of batch production practice has mastered the broken core law and solution to stabilize the quality of batch production, shell Breaking the core rate from the initial trial of more than 70% down to 10%, the casting of the core has been basically eliminated.