Electrochemical Machining (ECM), Electrochemical Grinding (ECG) Chemical dissolution Chemical Machining (CHM) using etchants 16MEE09 UNCONVENTIONAL MACHINING PROCESSES

NCM processes are categorized by the type of energy used for material removal Slideshare NON-TRADITIONAL MACHINING

The demand for high-strength temperature-resistant (HSTR) alloys, composites, and miniaturized components has rendered conventional machining (turning, milling) ineffective. This paper reviews five major classes of non-conventional machining processes: Mechanical (USM, AWJM), Electrical (EDM, WEDM), Electro-Chemical (ECM), and Thermal (LBM, PBM). Each process is analyzed based on its working principle, material removal mechanism, surface integrity, and economic viability. Results indicate that while EDM dominates die-sinking applications due to high accuracy (tolerance ±0.005 mm), ECM offers stress-free surfaces (Ra 0.05 µm) ideal for aerospace rotors. Laser machining provides the highest speed for micro-features but suffers from heat-affected zones. Hybrid processes are identified as the critical future direction.

Essentially the reverse of electroplating. It offers high material removal rates (MRR) without tool wear. 3. Electro-Thermal Processes These use heat to melt or vaporize the material.

| Parameter | Conventional | Non-Conventional | | :--- | :--- | :--- | | | Harder than workpiece (HSS, Carbide) | No physical contact or softer/conductive material (e.g., graphite) | | Mechanical Forces | High clamping forces required | Very low or zero forces | | Heat Generation | Frictional heat in shear zone | Controlled heat, or no heat (ECM, USM) | | Geometric Complexity | Limited by tool access | Virtually unlimited (holes at angles, micro-features) | | Material Hardness | Cutting becomes impossible above 45 HRC | No correlation with hardness |

Organize the processes into four main categories: