Table 3.

Center composite design scheme and response values.

No.	A	B	C	D	CS/MPa	STS/MPa
1	5	9	1.5	10	83.34	4.88
2	15	9	1.5	10	82.06	4.71
3	5	11	1.5	10	81.42	5
4	15	11	1.5	10	81.95	4.87
5	5	9	2.5	10	85.14	4.88
6	15	9	2.5	10	87.31	4.87
7	5	11	2.5	10	82.88	4.91
8	15	11	2.5	10	86.73	4.89
9	5	9	1.5	14	79.62	4.4
10	15	9	1.5	14	72.18	4.24
11	5	11	1.5	14	74.98	4.59
12	15	11	1.5	14	68.77	4.77
13	5	9	2.5	14	83.39	4.89
14	15	9	2.5	14	80.32	4.87
15	5	11	2.5	14	79.86	5.15
16	15	11	2.5	14	76.24	5.07
17	0	10	2	12	87.06	4.79
18	20	10	2	12	84.81	4.71
19	10	8	2	12	85.8	4.45
20	10	12	2	12	81.82	4.8
21	10	10	1	12	69.36	4.59
22	10	10	3	12	80.35	5.25
23	10	10	2	8	84.15	5.03
24	10	10	2	16	68.22	4.73
25	10	10	2	12	80.85	4.95
26	10	10	2	12	79.85	4.96
27	10	10	2	12	80.25	4.91
28	10	10	2	12	80.85	4.92
29	10	10	2	12	80.15	4.89
30	10	10	2	12	80.56	4.91