K465涡轮导向器熔模铸造工艺研究

Study on the Investment Casting of K465 Turbine Nozzle

涡轮导向器是在研某型号航天发动机的关键部件,采用K465铸造高温合金无余量整体熔模铸造而成。该部件由内锥、内环、叶片、外环和法兰五位一体构成,整体呈复杂框架结构,其叶片最薄处仅为0.7mm,且壁厚相差悬殊,铸造凝固过程易产生疏松、裂纹等缺陷,试制工艺难度很大。设计采用了蜡模分体压制,组合夹具精确定位,蜡模拼装组合成型的工艺方案,使叶片的一致性和尺寸精度得到了保证,获得了导向器熔模铸造用整体蜡模;通过浇注系统、铸造工艺的优化,解决了试制过程中出现的疏松和开裂问题,保证了铸件的冶金质量,研制出了合格的导向器铸件。

The nozzle, which is cast in K465 cast superalloy by investment casting, is one of the key components of the airspace engine. This component is a frame construction constituted of endocone, inner ring, vane, outer ring and flange, and the final thin thickness is 0.7 mm, the discrepancy of the wall thickness is great, the porosity and crack can be found easily in the process of casting, so it is very hard to produce. The adoption of split pattern and combined clamp ensured the uniformity and the dimensional precision of turbine nozzle blades, achieved the wax cast of turbine nozzle for investment casting; and the modification of pouring system and casting technique avoided the microporosity and thermal fragmentation of the cast, ensured the high metallurgy quality of cast, got an acceptable cast of turbine nozzle.