基于增材制造特性的带气膜孔叶片快速成型工艺技术研究

Study on rapid prototyping technology of blade with gas film hole based on manufacturing characteristics of additive manufacturing

航空发动机的涡轮叶片作为动力产生的主心脏,具有"弯"、"宽"、"掠"、"扭"、"薄"的特点,为了保证发动机的机能平稳性,常在叶片上设计微小气膜冷却孔结构以保证涡轮发动机的进口温度平衡。然而针对这种复杂直纹面上的微小孔加工在传统钻削加工与特种电化学加工中目前主要存在着加工效率低以及质量精度差的问题。为了解决减材制造复杂型面上的微小孔加工技术问题,提出了一种基于增材制造特性的带气膜孔叶片快速成型工艺方法。从增材制造的材料成型特性入手,建立快速成型中各阶段的成型工艺参数与成型质量间的作用关系,并结合多目标函数优化法利用Matlab软件实现成型工艺参数的最优化。实验结果表明,该方法只需传统减材制造的1/5周期即可快速成型出综合精度达IT8,且表面粗糙度在3μm以下的制件,因此该技术的研究对实现复杂异型结构产品的快速化制造奠定了理论基础。

The turbine blade of the aero engine is the main heart produced by the power,and has the characteristics of"bending","wide","plunder","twisting"and"thin".In order to ensure the smooth performance of the engine,the micro gas film hole structure is usually designed on the blade to ensure the inlet temperature balance of the turbine engine.However,in the traditional drilling and special electrochemical machining,the problems of low machining efficiency and poor quality exist in this kind of micro-hole machining on the complex straight surface.In order to solve the problem of micro-hole machining on complex surface,in this paper,a rapid prototyping method for blade with gas film hole is presented based on the characteristics of additive manufacturing:starting with the material forming characteristics of additive manufacturing,the relationship between the forming process parameters and the forming quality in each stage of rapid prototyping is established,and the optimization of forming process parameters is realized by using Matlab combined with the multi-objective function optimization method.The experimental results show that this method can produce products with a precision of IT8 and surface roughness below 3um in only 1/5 cycles of conventional material reduction.Therefore,the research of this technology lays a theoretical foundation for the rapid manufacturing of complex shaped products.