Question

Which of the following modern machining process, does not cause tool wear?

• A. Ultrasonic machining
• B. Electro-chemical machining
• C. Electric discharge machining
• D. Electron beam machining

Hint:

Remember the "Zero Wear" rule for Electro-Chemical Machining. Since it's a chemical reaction at the atomic level, the tool is never "tired" or "worn down" by the work.

Answer 1

The Correct Option is B

Modern or non-traditional machining processes use various forms of energy to remove material. The primary reason some processes cause tool wear while others do not lies in the physical mechanism of material removal. 1. Mechanism of Electro-chemical Machining (ECM): ECM is essentially the reverse of electroplating. It is based on Faraday's Laws of Electrolysis.

• In this process, the tool acts as the cathode and the workpiece as the anode, with a high-velocity electrolyte flowing between them.

• Material removal occurs atom by atom through

electrochemical dissolution.

• Because the material is removed via chemical ion exchange rather than heat or physical impact, there is absolutely no physical contact between the tool and the workpiece.

• Consequently, the tool does not undergo any thermal or mechanical stress, leading to

zero tool wear under ideal operating conditions.

2. Evaluating Tool Wear in Other Processes:

• Ultrasonic Machining (USM): Uses abrasive slurry driven by ultrasonic vibrations. The constant impact of abrasives causes significant mechanical wear on the tool over time.

• Electric Discharge Machining (EDM): Uses electrical sparks that generate extreme heat. While the spark removes material from the workpiece, it also causes "spark erosion" or thermal wear on the tool electrode.

• Electron Beam Machining (EBM): Uses a high-velocity stream of electrons that convert kinetic energy into heat. While the beam itself is "massless," the high temperatures and potential back-scattering of material can still lead to tool/aperture degradation.

3. Conclusion: Because Electro-chemical machining removes material through cold chemical dissolution without any physical or thermal contact, the tool remains virtually untouched throughout the process.