From the findings of DOE, it can be seen that DOE # 1 & 2 i.e. 575°C-10 / 8 has performed well in comparison to 560°C-10 hrs. Out of this finding there was no meaning to take trial with DOE # 4 i.e. with 560°C – 8 hrs. The optimum result decided was 575°C for 8 Hrs.