A Study on Using the Additive Manufacturing Process for the Development of a Closed Pump Impeller for Mechanically...

Area of Science:

• Materials Science
• Mechanical Engineering
• Aerospace Engineering

Background:

• The efficiency of centrifugal pumps in mechanically pumped fluid loops (MPFLs) is critically dependent on the dimensional accuracy and surface quality of closed impellers.
• Additive manufacturing (AM) offers potential for fabricating complex geometries like impellers for space applications.

Purpose of the Study:

• To define and optimize the additive manufacturing process for Inconel 625 closed impellers for MPFL systems.
• To evaluate the impact of building orientation on dimensional accuracy and surface quality.
• To assess post-processing techniques for enhancing impeller performance.

Main Methods:

• Selective laser melting (SLM) was used to fabricate three closed impellers with varying building orientations.
• Dimensional accuracy and surface roughness were evaluated for each impeller.
• Abrasive flow machining (AFM) was investigated as a post-processing method.

Main Results:

• Increased building orientation generally improved geometrical stability and surface roughness.
• Blade thickness showed minor deviations from target values.
• AFM post-processing significantly enhanced surface quality, particularly in inaccessible areas.

Conclusions:

• Additive manufacturing, specifically SLM, is a viable technology for producing closed impellers for space-based MPFL systems.
• Optimized building orientations and AFM post-processing are crucial for achieving desired impeller performance.
• Further refinement of post-processing techniques can further enhance AM capabilities for space applications.