Analysis of variance

Process parameters have been known to determine the quality of weldments in welding operations. Therefore the process parameters have to be manipulated to determine the desirable quality of the weldment. In doing this, the Taguchi method was applied to optimize these process parameters. The response obtained from the welding operation was the Impact strength of the weldments. From using the Taguchi method, it was derived that the optimum process parameters is A3,B1,C3. The analysis of variance was computed to determine the level of contribution of each of the process parameter to the quality level of the weldment.
It was investigated that voltage contributed most having a total of 14.42% of the quality level of the weldment, followed by the welding current, with a value of 7.94% and gas flow rate being the least with a contribution of 2.04%. A confirmation test was carried out to validate the inference that A3,B1,C3 is the optimum process parameters. The signal to noise ratio of the existing process parameters of A2 B3, C1 was determined to be 40.3997dB, whereas, the optimum welding process has a signal to noise ratio of 42.8796 dB. This shows that there is an improvement of 2.4799 dB of the optimum process parameters over the existing one. The Impact Energy of the weldment produced by the welding operation made by using the optimum process parameters has 12 J more than the Impact Energy obtained from the weldment made by using the existing process parameters.
In this study, the Taguchi method was useful in improving the quality of weldment made by applying the optimum process parameters obtained.