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

Table 5

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

Source	SS	DOF	MS	𝐹-Value	𝑃>𝐹	At 95% CI	% Contribution
Model	3.08	10	0.31	145.26	<0.0001	Significant
Pulse on time	1.64	1	1.64	775.10	<0.0001	Significant	55.0
Pulse off time	0.84	1	0.84	396.22	<0.0001	Significant	28.0
Peak current	0.23	1	0.23	108.54	<0.0001	Significant	8.0
Spark gap voltage	0.18	1	0.18	85.03	<0.0001	Significant	6.0
Pulse off time^2	0.013	1	0.013	6.36	0.0155	Significant	0.41
Wire feed^2	0.068	1	0.068	32.18	<0.0001	Significant	2.15
Wire tension^2	0.019	1	0.019	8.90	0.0047	Significant	0.6
Pulse on time × peak current	0.086	1	0.086	40.62	<0.0001	Significant	2.71
Lack of fit	0.087	38	0.002295	2.91	0.1173	Not significant
𝑅^2=0.9712
𝑅^2adjusted = 0.9646
Predicted 𝑅^2=0.9527

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