OPTIMIZATION OF A NONCONVENTIONAL MACHINING PROCESS USING MULTI-CRITERIA SELECTION METHODS

Determining the optimal parameters for a process technology requires a full analysis of all the principles and factors that influence it. Nonconventional technologies are more and more present in modern manufacturing processes, so determining the values of the technological and economic parameters is vital. In this paper, multi-criteria methods (ELECTRE, TOPSIS) were used to determine the importance of the criteria and to establish the best combination of parameters (discharge time, off time, average lateral spark gap, lateral roughness, frontal roughness, velocity of erosion) in an electrical discharge machining process with massive electrode for C120 steel at 85V voltage. The dimensions of the depressions in a steel piece depending on the energy or duration of the pulses, and the influence of the moving speed of the semi-finished product on productivity can be also determined. Various multi-criteria decision-making methods are available to help the designers in choosing the decisive course of actions. In the discrete form of multi-criteria decision-making problems, the work flow is confronted with a decision-matrix formed from the information of some alternatives on different criteria. A software application was created that allows the user to enter only the desired parameters and the criteria that must be strictly respected, and the program will choose in a very short time the optimal combination of the available values.