Development of an EN8 Steel Stepped Rotor by a Novel Engraving Milling Technique

Area of Science:

• Mechanical Engineering
• Manufacturing Processes
• Materials Science

Background:

• Rotors and impellers are critical rotating components in pumps and compressors.
• Traditional manufacturing methods for rotors can be complex and costly.
• Surface quality, indicated by average roughness, is crucial for rotor performance.

Purpose of the Study:

• To detail the development of small rotors using a novel computer numerical control engraving milling machine (CNC-EMM) technique.
• To investigate the influence of CNC-EMM parameters on rotor surface quality.
• To establish CNC-EMM as a viable alternative for rotor blade fabrication.

Main Methods:

• Fabrication of twenty-eight stepped rotors from EN8 steel cylindrical blanks.
• Utilizing a CNC-EMM with a 4 mm tungsten carbide end mill cutter.
• Applying the Box-Behnken Design (BBD) of Experiments (DoE) to optimize CNC-EMM parameters (rotational speed, feed, plunge feed).
• Analysis of Variance (ANOVA) to determine parameter influence on average roughness (R).

Main Results:

• Identified feed and plunge feed as the most influential parameters affecting rotor surface quality.
• Achieved a minimum average roughness (R) value of 0.11 µm for the rotor blades.
• Field-emission scanning electron microscopy (FE-SEM) confirmed uniform tooth profiles and minor burr formation.

Conclusions:

• Computer numerical control engraving milling (CNC-EMM) is demonstrated as a feasible and effective method for manufacturing small rotors.
• The study provides valuable insights into parameter optimization for achieving high-quality rotor surfaces.
• This research offers a new manufacturing approach for engineers and researchers in the field of turbomachinery components.