Application of additive technologies for manufacturing turbine stator parts in aircraft engines

Abstract

Continuous development of additive technologies and fast prototyping methods makes it possible to use them in manufacturing of complex shape models to a high precision. The traditional technological manufacture process of critical hot gas path parts by investment casting is expensive and time consuming in view of its technological complexity. It is related to the wax casting process which provides complex profiles with high geometrical accuracy. The acceleration of the investment casting process should increase the productivity of the manufacturing process of such hot gas path parts as the turbine stator, however, it is not allowed to decrease the geometric accuracy of the finished product. The aim of this work is to compare technological processes for manufacturing turbine stator parts at various temperatures using the fast prototyping method (wax casting in silicone molds). The dimensional analysis of the stator castings showed that casting in silicone molds provides the required geometric accuracy. Thus, silicone molds can be viewed as a good cost-effective solution for small-scale or pilot production of high-precision complex parts in gas turbine engines. This article describes the procedure for the integrated application of additive technologies and thermographic analysis to accelerate the investment casting process by determining the optimal temperature conditions and cooling period. Ultimately, it reduces the duration of the production cycle and the cost of the finished product while retaining the quality characteristics.