Non-traditional machining: dielectric usage In which non-traditional machining process is a dielectric fluid essential to initiate and sustain controlled material removal?
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AElectro-chemical machining (ECM)
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BUltrasonic machining (USM)
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CElectro-discharge machining (EDM)
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DLaser beam machining (LBM)
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EAbrasive water jet machining (AWJM)
Answer
Correct Answer: Electro-discharge machining (EDM)
Explanation
Introduction / Context:Non-traditional processes remove material via chemical reactions, thermal energy, mechanical abrasion, or electrical discharges. Each process uses a different working medium.
Given Data / Assumptions:
- EDM requires spark discharges between tool and work.
- Dielectric fluid fills the spark gap.
- Typical dielectrics: kerosene, deionized water, specialized oils.
Concept / Approach:In EDM, the dielectric provides insulation until breakdown voltage is reached, then collapses to form a spark channel that melts/vaporizes a tiny volume of work material. It also flushes debris and cools the zone, restoring dielectric strength between discharges.
Step-by-Step Solution:Establish need for controlled sparking → requires dielectric medium.Identify process using sparks for erosion → EDM.Therefore, dielectric is essential in EDM.
Verification / Alternative check:Process schematics always depict a dielectric tank or flushing system in EDM setups.
Why Other Options Are Wrong:
- ECM uses an electrolyte, not a dielectric; it relies on ionic dissolution.
- USM uses abrasive slurry mechanically; no dielectric needed.
- LBM uses focused light in air/inert gas; again, no dielectric.
Common Pitfalls:Confusing electrolyte (conductive) with dielectric (insulating); inadequate flushing causes arcing and poor surface finish in EDM.
Final Answer:Electro-discharge machining (EDM)