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

Table 5

ANOVA results.

Analysis of variance for surface roughness
Source	DF	Seq. SS	Contribution (%)	Adj. SS	Adj. MS	F value	value
Ampere	1	4.1366	49.34	4.1366	4.13665	91.78	0.000001
Time on (μs)	2	3.4632	41.31	3.4632	1.73160	38.42	0.000006
Time off (μs)	2	0.2430	2.90	0.2430	0.12150	2.70	0.107923
Error	12	0.5409	6.45	0.5409	0.04507
Total	17	8.3837	100.00		R-sq: 93.55%
Analysis of variance for hole diameter
Source	DF	Seq. SS	Contribution (%)	Adj. SS	Adj. MS	F value	value
Ampere	1	0.006385	10.44	0.006385	0.006385	10.75	0.006601
Time on (μs)	2	0.036316	59.38	0.036316	0.018158	30.57	0.000020
Time off (μs)	2	0.011332	18.53	0.011332	0.005666	9.54	0.003316
Error	12	0.007129	11.66	0.007129	0.000594
Total	17	0.061161	100.00		R-sq: 88.34%
Analysis of variance for crater diameter
Source	DF	Seq. SS	Contribution (%)	Adj. SS	Adj. MS	F value	value
Ampere	1	3276.67	55.65	3276.67	3276.67	283.97	0.000000001
Time on (μs)	2	2401.05	40.78	2401.05	1200.53	104.04	0.000000026
Time off (μs)	2	71.88	1.22	71.88	35.94	3.11	0.081360841
Error	12	138.47	2.35	138.47	11.54
Total	17	5888.07	100.00		R-sq: 97.65%
Variance analysis for wear amount
Source	DF	Seq. SS	Contribution (%)	Adj. SS	Adj. MS	F value	value
Ampere	1	0.007483	6.75	0.007483	0.007483	3.07	0.105
Time on (μs)	2	0.063100	56.92	0.063100	0.031550	12.93	0.001
Time off (μs)	2	0.010987	9.91	0.010987	0.005493	2.25	0.148
Error	12	0.029288	26.42	0.029288	0.002441
Total	17	0.110858	100.00		Rq: 73.58%
Variance analysis for wear rate
Source	DF	Seq. SS	Contribution (%)	Adj. SS	Adj. MS	F value	value
Ampere	1	0.000044	51.42	0.000044	0.000044	32.17	0.0001
Time on (μs)	2	0.000004	4.35	0.000004	0.000002	1.36	0.2930
Time off (μs)	2	0.000021	25.04	0.000021	0.000011	7.83	0.0067
Error	12	0.000016	19.18	0.000016	0.000001
Total	17	0.000086	100.00		R-sq: 80.82%
Analysis of variance for processing time
Source	DF	Seq. SS	Contribution (%)	Adj. SS	Adj. MS	F value	value
Ampere	1	235298	78.02	235298	235298	154.36	0.00000001
Time on (μs)	1	3536	1.17	3536	3536	2.32	0.14999385
Time off (μs)	1	41419	13.73	41419	41419	27.17	0.00013152
Error	14	21341	7.08	21341	1524
Total	17	301594	100.00		R-sq: 92.92%