Application of response surface methodology for prediction and modeling of surface roughness in ball end milling of OFHC copper

Journal of Materials Science: Materials in Engineering

Table 5 Analysis of variance for mean roughness depth R_z (μm) (reduced quadratic model)

Source	DF	Sum of squares	Adj. mean square	F value	p value	Cont. %	Remarks
Regression	10	16.3434	1.6343	1220.36	0.000		Significant
Linear	4	3.8661	0.9665	721.70	0.000
f _z	1	0.2904	0.2904	216.84	0.000	1.77	Significant
a _p	1	0.7491	0.7491	559.33	0.000	4.57	Significant
a _e	1	2.7473	2.7472	2051.38	0.000	16.78	Significant
V _c	1	0.0793	0.0794	59.25	0.000	0.48	Significant
Square	4	12.4276	3.1069	2319.92	0.000
f_z × f_z	1	3.6310	3.6310	2711.28	0.000	22.18
a_p × a_p	1	3.2831	3.2831	2451.52	0.000	20.05
a_e × a_e	1	5.2588	5.2588	3926.78	0.000	32.12
V_c × V_c	1	4.1584	4.1584	3105.06	0.000	25.40
Interaction	2	0.0497	0.0249	18.56	0.000
f_z × a_e	1	0.0272	0.0272	20.33	0.000	0.14
a_e × V_c	1	0.0225	0.0225	16.80	0.001	0.16
Error	20	0.0268	0.0013
Lack-of-fit	14	0.0236	0.0017	3.22		0.079	Not significant
Pure error	6	0.0031	0.0005
Total	30	16.3702
					R ²		0.9984
					\( {R}_{adj.}^2 \)		0.9975