Experimental and Statistical Investigation of Machinability of AISI D2 Steel Using Electroerosion Machining Method in Different Machining Parameters

Table 7

Gray relational analysis and ranking.

Exp No.	Normalization						Coefficient matrix
	Ra (μm)	HD (mm)	CD (μm)	MRR (g/min)	PT (min)	WA (g)	Ra (μm)	HD (mm)	CD (μm)	MRR (g/min)	PT (min)	WA (g)	Gray degree
1	0.894	0.848	0.929	0.182	0.379	0.396	0.825	0.767	0.875	0.379	0.446	0.453	0.624
2	0.976	0.866	0.955	0.063	0.781	0.396	0.954	0.789	0.918	0.348	0.695	0.453	0.693
3	1.000	1.000	1.000	0.030	0.888	0.218	1.000	1.000	1.000	0.340	0.817	0.390	0.758
4	0.502	0.408	0.621	0.109	0.587	0.439	0.501	0.458	0.569	0.360	0.548	0.471	0.484
5	0.574	0.565	0.691	0.012	0.979	0.116	0.540	0.535	0.618	0.336	0.960	0.361	0.558
6	0.579	0.652	0.756	0.000	1.000	0.000	0.543	0.589	0.672	0.333	1.000	0.333	0.579
7	0.444	0.362	0.574	0.162	0.582	0.812	0.473	0.439	0.540	0.374	0.545	0.727	0.516
8	0.488	0.540	0.600	0.126	0.676	0.759	0.494	0.521	0.555	0.364	0.607	0.675	0.536
9	0.507	0.598	0.623	0.110	0.864	1.000	0.504	0.554	0.570	0.360	0.786	1.000	0.629
10	0.401	0.683	0.534	1.000	0.000	0.386	0.455	0.612	0.518	1.000	0.333	0.449	0.561
11	0.454	0.696	0.608	0.607	0.052	0.261	0.478	0.622	0.561	0.560	0.345	0.403	0.495
12	0.479	0.857	0.615	0.262	0.164	0.040	0.489	0.778	0.565	0.404	0.374	0.342	0.492
13	0.302	0.310	0.295	0.680	0.042	0.310	0.417	0.420	0.415	0.610	0.343	0.420	0.437
14	0.317	0.583	0.310	0.398	0.144	0.340	0.423	0.545	0.420	0.454	0.369	0.431	0.440
15	0.386	0.673	0.345	0.189	0.282	0.158	0.449	0.604	0.433	0.381	0.411	0.373	0.442
16	0.000	0.000	0.000	0.592	0.104	0.601	0.333	0.333	0.333	0.551	0.358	0.556	0.411
17	0.103	0.054	0.048	0.314	0.238	0.498	0.358	0.346	0.344	0.422	0.396	0.499	0.394
18	0.240	0.470	0.085	0.193	0.337	0.330	0.397	0.486	0.353	0.382	0.430	0.427	0.413

Ra: surface roughness, HD: hole diameter, CD: crater diameter, WR: wear rate, PT: processing time, WA: wear amount.