56
J. Karloopia et al.
Table 4 ANOVA for ultimate tensile strength
Source
DF
Adj SS
Adj MS
F-value
P-value
Model
6
200.164
33.361
23.06
0.158
Linear
3
186.593
62.198
42.99
0.112
TV
1
28.088
28.088
19.41
0.142
TWS
1
137.465
137.465
95.02
0.065
TRS
1
21.041
21.041
14.54
0.163
2-way interaction
3
13.571
4.524
3.13
0.389
TV * TWS
1
3.269
3.269
2.26
0.374
TV * TRS
1
8.959
8.959
6.19
0.243
TWS * TRS
1
1.343
1.343
0.93
0.512
Error
1
1.447
1.447
Total
7
201.611
Table 5 ANOVA for elongation
Source
DF
Adj SS
Adj MS
F-value
P-value
Model
6
0.99897
0.166496
30.2
0.138
Linear
3
0.88584
0.295279
53.57
0.1
TV
1
0.14851
0.148512
26.94
0.121
TWS
1
0.66701
0.667012
121
0.058
TRS
1
0.07031
0.070313
12.76
0.174
2-way interaction
3
0.11314
0.037713
6.84
0.272
TV * TWS
1
0.01201
0.012012
2.18
0.379
TV * TRS
1
0.07801
0.078013
14.15
0.165
TWS * TRS
1
0.02311
0.023113
4.19
0.289
Error
1
0.00551
0.005512
Total
7
1.00449
99.28 and 94.98% for the ultimate tensile strength (UTS), (ii) 99.45 and 96.16% for
elongation, and (iii) 99.69 and 97.82% for the microhardness.
The final regression equation for each response parameter using MINITAB-19
software is as follows;
UTS = 144.3 + 15.64 TV − 0.524 TWS + 0.0029 TRS − 0.1279 TV ∗ TWS
− 0.01898 TV ∗ TRS + 0.000367 TWS ∗ TRS
(1)