What are the advantages of electron beam welding in blade repair?

• A. It is slower and more expensive but stronger
• B. Permits the reworking of many compressor blades formerly thought to be unserviceable and results in a strength factor equal to a new blade
• C. It can only be used on non-ferrous metals
• D. It cannot be used on turbine blades

Answer: (B)

Electron beam welding enables concentrated, high-energy heat input in a controlled vacuum environment, which is ideal for repairing thin, complex blade shapes without causing excessive distortion. This precision allows reworking blades that were once considered unserviceable by filling cracks, rebuilding thinning sections, or repairing damaged tips while preserving the blade’s geometry and integrity.

The key advantage is that the repaired blade can achieve strength comparable to a new blade, meaning the repair restores the part’s structural performance to near-original specifications. In practice, this makes it possible to salvage high-cost compressor blades and extend service life without sacrificing reliability, which is especially valuable for high-performance turbine materials where maintaining microstructure and mechanical properties is critical.

Other statements don’t fit as well because EBW is not inherently slower or more expensive in all cases, and it is not limited to non-ferrous metals or restricted from turbine blades. It is applicable to the alloys used in blades, including nickel-based and other high-temperature materials, and it is indeed used for turbine blade repair.