What method should be used to finish a compressor blade that has damage such as burrs or nicks?

What method should be used to finish a compressor blade that has damage such as burrs or nicks?

• A. Coarse file
• B. Sandblast
• C. Fine oil stone
• D. Grinding wheel

Answer: (C)

The main idea is to pick a finishing method that removes small edge damage without changing the blade’s geometry or creating new defects. A fine oil stone is ideal because it allows precise, controlled removal of burrs and nicks, leaving a smooth edge without removing excessive material or altering the airfoil profile. This preserves the blade’s performance and reduces the risk of stress concentrations that could lead to fatigue. Using a coarse file would remove material too quickly and can distort the edge or blade contour. Sandblasting would roughen or pit the surface and isn’t suitable for restoring a precise edge. A grinding wheel would remove material aggressively, generate heat, and potentially cause microcracks or alter the edge radius, compromising the blade’s integrity. After finishing, inspect the edge to ensure no remaining burrs and that the blade still meets specifications.

The main idea is to pick a finishing method that removes small edge damage without changing the blade’s geometry or creating new defects. A fine oil stone is ideal because it allows precise, controlled removal of burrs and nicks, leaving a smooth edge without removing excessive material or altering the airfoil profile. This preserves the blade’s performance and reduces the risk of stress concentrations that could lead to fatigue.

Using a coarse file would remove material too quickly and can distort the edge or blade contour. Sandblasting would roughen or pit the surface and isn’t suitable for restoring a precise edge. A grinding wheel would remove material aggressively, generate heat, and potentially cause microcracks or alter the edge radius, compromising the blade’s integrity. After finishing, inspect the edge to ensure no remaining burrs and that the blade still meets specifications.