The CNC grinding of integrated impeller with electroplated CBN wheel

The profile precision of integrated impeller is very important for the aerodynamic performance of aero-engines. With the wide application of difficult-to-cut materials in aerospace industry, the milling process is difficult to meet the further processing requirements of integrated impeller due to the kinds of limitations such as short tool life, cutting vibration, and great cutting force. Utilizing the ability to remove small allowance and the low continuous grinding force, the CNC high-speed grinding of integrated impeller with electroplated CBN wheel is presented to reduce the profile error of blade surface and improve the surface quality. Based on the analysis of wheel design, grinding process optimization and surface integrity measurement, the grinding experiment on GH4169 integrated impeller with CBN wheel is carried out. The results show that the average profile error of blades is about 0.027 mm while the average distortion angle is about 0.023°. Compared with the milling process, the machining error of blades can be reduced by about 50 %, which prove that the high-speed grinding process using the super-hard abrasive wheel is effective in the machining GH4169 integrated impeller.