Process identification by mechanism of metal removal When metal is removed by erosion caused by rapidly recurring electrical spark discharges between a shaped tool and a conductive workpiece, the process is called:

Introduction / Context:
Advanced machining processes are categorized by their dominant energy interaction with the workpiece. EDM is a thermal erosion process relying on controlled spark discharges in a dielectric to shape conductive materials, independent of mechanical cutting forces.

Given Data / Assumptions:

• Tool and work are conductive.
• A pulsed power supply generates controlled discharges.
• Dielectric fluid fills the inter-electrode gap.

Concept / Approach:
Each spark melts and vaporizes a tiny amount of material from both the tool and work surface. Flushing removes debris, leaving a characteristic cratered surface. This mechanism distinguishes EDM from other nontraditional processes such as ECM (ionic dissolution) or USM (abrasive micro-chipping).

Step-by-Step Solution:
Recognize the keyword “spark discharges” indicating an electrical breakdown event.Associate dielectric and pulsed power with EDM.Select EDM as the matching process.

Verification / Alternative check:
EDM can produce sharp internal corners and deep cavities in hardened steels where conventional cutting is difficult—typical application evidence.

Why Other Options Are Wrong:
ECM uses electrochemical dissolution (no sparks). USM uses high-frequency vibrations with slurry abrasives. LBM uses a focused laser for melting/ablation. Thus, they do not match the “spark erosion” description.

Common Pitfalls:
Confusing EDM with ECM due to both being “non-traditional” and fluid-based; remember that only EDM involves sparking and dielectric breakdown.

Final Answer:
Electro-discharge machining (EDM)