Experimental Investigation on Material Transfer Mechanism in WEDM of Pure Titanium (Grade-2)

Table 4

The analysis of variance for main and interaction effects of parameters on overcut.

Source	SS	DOF	MS	𝐹-value	Prob. > 𝐹	At 95% CI	% Contribution
Model	1101.81	12	91.82	30.71	<0.0001	significant
Pulse on time	368.17	1	368.17	123.16	<0.0001	significant	30.07
Pulse off time	352.67	1	352.17	117.97	<0.0001	significant	28.76
Peak current	176.04	1	176.04	58.89	<0.0001	significant	14.37
Spark gap voltage	28.17	1	28.17	9.42	<0.0038	significant	2.30
Pulse off time^2	14.22	1	14.22	4.76	0.0350	significant	1.16
Peak current^2	76.13	1	76.13	25.47	<0.0001	significant	6.21
Wire feed^2	13.40	1	13.40	4.48	0.0403	significant	1.09
Wire tension^2	54.41	1	54.41	18.20	<0.0001	significant	4.44
Pulse on time × spark gap voltage	36.00	1	36.00	12.04	0.0012	significant	2.94
Pulse off time × peak current	21.13	1	21.13	7.07	0.0111	significant	1.72
Lack of fit	115.73	36	3.21		0.1719	not significant
𝑅^2=0.8999
𝑅^2 adjusted = 0.8706
Predicted 𝑅^2=0.8191

SS: sum of square, DOF: degree of freedom, MS: mean square, 𝐹-value: Fisher value.