MULTICRITERIA OPTIMIZATION FOR DETERMINING LOW WEAR OF THE SURFACE PRODUCED IN ELECTRICAL DISCHARGE MACHINING

Sivaprasad P V, A. Mandal

Abstract: Surface roughness has a significant effect on the functional performance of two mating surfaces. One of the objectives of this work is to develop mathematical models based on the design of experiments to correlate the controllable process parameters (Current, Pulse on time, Inter-electrode gap and Electrode rotation) of EDM to surface roughness parameters such as Sq, Ssk, Sku and SHtp. Using Central Composite Design the desired mathematical models are developed. However, using only a single 3D roughness parameter will not be sufficient for evaluating functional performance of a surface. So, it is necessary to use multiple 3D surface parameters for characterizing the functional performance of a surface. The functional requirement such as low wear rate during service depends on a number of surface roughness parameters such as Sq, Ssk, Sku and SHtp. Hence, the next objective is to use multi-criteria optimization based on desirability function to find out the value of operating parameters that will ensure low wear rate. The values of operating parameters for low wear rate for lubricated and unlubricated conditions are found. SG Iron of grade 450/12 (pearlitic matrix) is used as workpiece material as it is an important engineering material and limited information is available on machining of SG iron using EDM

Keywords: EDM, Surface Roughness, Central Composite Design, Multi-Criteria Optimization, Desirability Function.

DOI: https://doi.org/10.15623/ijret.2017.0602003