Adaptive machining framework for the leading/trailing edge of near-net-shape integrated impeller

As a result of the recently increasing demands on high-performance machining technology in the aero-engine industry, the near-net shape forming technique can be suitable for many integrated impellers. However, the previous forming deformation can raise serious problems for the secondary NC machining of non-formed area, which is mostly applicable for leading/trailing edge (LE/TE) and its adjacent area. It is even worse that non-designed shape and dimension of LE/TE may be responsible for the deteriorated aerodynamic performance and subsequent high in-service cost, especially when its radius is small. Based on previous efforts, this paper presents a 5-axis adaptive machining framework for the LE/TE of near-net-shape integrated impeller. On-machine measurement (OMM) with a touch-trigger probe is utilized to digitalize the impeller. The distribution and uncertainty of sampling points are taken into account with data processing. Through the comparison between the measured and nominal geometric parameters, the impeller profile can be reconstructed sequentially on each tandem cascade. Among this, the camber line deformation emphasizes the functional significance of design intent and the thickness distribution conforms the processed data at most degree. Utilizing the ability to remove small allowance and the low continuous grinding force, the 5-axis CNC grinding with electroplated cubic boron nitride (CBN) wheel is carried out. Moreover, typical examples are used to demonstrate the effectiveness and superiority of this strategy.