Saad  Hameed Al-Shafaie, 
    Multi-Objective Optimization to Improve Surface Integrity in WEDM of
AL/WC<sub>p</sub> Metal Matrix Composites Using Grey Relational Analysis,
    Journal of Engineering and Applied Sciences,
    Volume 13,Issue 24,
    2018,
    Pages 10173-10181,
    ISSN 1816-949x,
    jeasci.2018.10173.10181,
    (https://makhillpublications.co/view-article.php?doi=jeasci.2018.10173.10181)
    Abstract: Demand for low weight to strength ratio for specific application in aerospace components and automobile created a field for advance studies on Metal Matrix Composites (MMCs). The main response selected to evaluate the processes are White Layer Thickness (WLT) and Surface Crack Density (SCD) whereas the corresponding machining conditions are discharge current (I<sub>p</sub>), Voltage (V), pulse on Time (T<sub>on</sub>) and pulse off Time (T<sub>off</sub>). Wire Electrical Discharge Machining (WEDM) process is principally with multi response, thus, Grey Relational Analysis (GRA) is especially adopted to decide the optimum combination of machining parameters of Al6061 reinforced with volume fraction of 10% WC<sub>p</sub>. Design of experiments was carried out based on a standard L<sub>27</sub> orthogonal array of Taguchi method. Minitab16 Software was performed to analyze the results obtained from experimental runs at confidence level 95%. For the present experimental study, it is observed that WLT and SCD are mainly affected by all process parameters except T<sub>off</sub> has little effect on the SCD. The values corresponding to the response parameters were calculated using mathematical formulas and confirmed by the verification experiment. The values of confirmation tests, all being found to be quite satisfactory (10.92% in the worst case), prove the efficacy and reliability of the suggested approach.
    Keywords: WEDM;MMCs;Taguchi method;ANOVA;GRA;surface integrity