Table 13 Comparison of the present research with the state of the art.

Singh⁵²

Al6061–SiC MMC

Brass, Copper

I, T_ON, T_OFF

Brass → higher MRR;

Copper → lower TWR

Precise optimal parameter set for copper vs. graphite on Al–SiC is missing

✓

✓

×

✓

×

Uddin⁵³

General EDM workpieces (tool study)

Copper–Graphite composite electrodes

Electrode composition, current, T_ON/T_OFF

Composite electrodes outperform pure copper (lower TWR);

Findings are not specific to Al–SiC.

Copper vs. graphite quantitative study on Al–SiC MMC is missing

×

×

×

✓

×

Abbas⁵⁴

Al/SiC/Gr hybrid composites

Multiple tools

Current, T_ON, T_OFF;

Empirical models for MRR and TWR;

Comparative trends for different tool materials;

Parameter sets & direct % improvement comparisons are different from the present study

✓

✓

×

✓

✓

Debnath⁵⁵

Al–SiC variants

Typical EDM electrodes

T_ON, T_OFF, I, SiC wt%

ANN/GEP models;

T_ON and current as dominant; gives goodness-of-fit metrics;

Numerical predictions

Lacks a concise, experimentally validated optimal setting for copper vs. graphite on Al–SiC

✓

✓

×

✓

×

Nowicki⁵⁶

EDM with graphite electrodes

Graphite

Current, T_ON/T_OFF; weighing method for MRR/TWR

Measured MRR/TWR with experimental procedure;

Single-electrode focus (graphite)

Comparative study is missing

×

×

×

✓

×

Jagdale et al.⁵⁷

Ti–6Al–4V

Graphite, Copper, Brass

T_ON, T_OFF, I

Electrode-dependent MRR/TWR trends;

Copper is often favourable for MRR in some setups

Study was on Ti-6Al-4 V not on Al–SiC MMC

×

✓

×

✓

×

Sahu et al.⁵⁸

Various EDM tests reported

Cu-SiC composite electrodes vs. conventional

I, T_ON, T_OFF

22% improvement in MRR and ≈ 47% reduction in TWR for certain composite tools vs. baseline copper

Copper vs. graphite side-by-side numeric comparison is missing for Al–SiC MMC

×

×

×

✓

×

Ayhan et al.⁵⁹

Al2024-T3 (not Al–SiC)

Copper, Brass, Graphite (contextual)

Multi-objective optimization, robust design

Robust optimization methods and objective tradeoffs;

Valuable for methodology; not focused on Al–SiC MMC.

×

×

✓

✓

✓

Sivasankaran et al.⁶⁰

MMCs (EDM tests with copper electrodes)

Copper (conventional & DMLS)

I, T_ON/T_OFF; electrode manufacturing method

MRR comparisons; Copper electrodes perform well;

Focus on copper manufacturing/processing; Direct copper vs. graphite side-by-side numeric % improvements are missing

×

×

×

✓

×

Karim et al.⁶¹

Electrode design methods (arrays, hollow)

Graphite (array/hollow) and design variants

Geometric design, T_ON, T_OFF

Electrode geometry significantly affects MRR/TWR;

Adds electrode-design angle; gap remains for material-level side-by-side numeric optima for Al–SiC.

×

×

×

✓

×

Ahmed⁶²

Tool steels / multiple materials

Copper vs. Graphite (comparative context)

I, T_ON/T_OFF

Copper gives higher MRR and lower electrode wear compared to graphite for steels

Corroborative evidence across materials; not specific to Al–SiC MMC with a Box–Behnken DOE on the same composition.

×

✓

✓

×

×

Rajendran et al.⁶³

Al/SiC and hybrid composites

Multiple electrodes (varied)

I, T_ON, T_OFF multiobjective optimization

Multiobjective optimized parameter sets and performance metrics;

Objectives are not always comparable to a specific Al–SiC composition.

✓

✓

×

✓

×