Table 2 Analysis of variance for response measures.
A. Machining time | |||||||
|---|---|---|---|---|---|---|---|
Source | DF | Seq SS | Contribution | Adj SS | Adj MS | F-value | P-value |
Current (A) | 2 | 178,050 | 57.62% | 178,050 | 89025.1 | 149.98 | 0.000 |
Pulse duration (µs) | 3 | 61,272 | 19.83% | 61,272 | 20424.1 | 34.41 | 0.000 |
Pulse interval (µs) | 3 | 46,562 | 15.07% | 46,562 | 15520.6 | 26.15 | 0.000 |
Error | 39 | 23,149 | 7.49% | 23,149 | 593.6 | – | – |
Total | 47 | 309,034 | 100.00% | – | – | – | – |
S = 24.3634; R2 = 92.51%; R2(adj) = 90.97%; PRESS = 35066.5; R2(pred) = 88.65% | |||||||
B. Material removal rate | |||||||
Source | DF | Seq SS | Contribution | Adj SS | Adj MS | F-value | P-value |
Current (A) | 2 | 0.004962 | 51.55% | 0.004962 | 0.002481 | 142.50 | 0.000 |
Pulse duration (µs) | 3 | 0.002369 | 24.62% | 0.002369 | 0.000790 | 45.37 | 0.000 |
Pulse interval (µs) | 3 | 0.001615 | 16.78% | 0.001615 | 0.000538 | 30.92 | 0.000 |
Error | 39 | 0.000679 | 7.05% | 0.000679 | 0.000017 | – | – |
Total | 47 | 0.009625 | 100.00% | - | – | – | – |
S = 0.0041724; R2 = 92.95%; R2(adj) = 91.50%; PRESS = 0.0010285; R2(pred) = 89.31% | |||||||
C. Surface roughness | |||||||
Source | DF | Seq SS | Contribution | Adj SS | Adj MS | F-value | P-value |
Current (A) | 2 | 14.9317 | 80.63% | 14.9317 | 7.46586 | 439.60 | 0.000 |
Pulse duration (µs) | 3 | 2.7551 | 14.88% | 2.7551 | 0.91838 | 54.08 | 0.000 |
Pulse interval (µs) | 3 | 0.1693 | 0.91% | 0.1693 | 0.05645 | 3.32 | 0.029 |
Error | 39 | 0.6624 | 3.58% | 0.6624 | 0.01698 | – | – |
Total | 47 | 18.5185 | 100.00% | – | – | – | – |
S = 0.130320; R2 = 96.42%; R2(adj) = 95.69%; PRESS = 1.00333; R2(pred) = 94.58% | |||||||
