Optimization of wire electrical discharge machining parameters for cutting electrically conductive boron carbide

In this work, Pure boron carbide (B4C) was consolidated using spark plasma sintering (SPS) at 2050 degrees C with a dwell of 10 min under 50 MPa uniaxial pressure in Argon atmosphere. The sintered specimen was >99% dense and offered characteristic Vickers hardness and fracture toughness of 31.4 GPa and 4.21 MPa-m(0.5), respectively, at 4.9 N indentation load. The specimen showed satisfactory wire electrical discharge machining (WEDM) performance because of its good electrical conductivity. The design of experiment (DOE) was arranged by 132 orthogonal array (OA) between the machining input parameters namely pulse on-time, pulse off-time, pulse peak current, dielectric fluid pressure and servo feed rate and the output responses like machining speed and surface roughness (R-a). Regression models were employed to establish the numerical correlation between the machining parameters and output responses. Experimental observations were utilized to formulate the first-order regression models to predict responses of WEDM. The optimized input parameters were 27 mu s pulse on time, 48 mu s pulse off time, 180 A pulse peak current, 7 kg/cm(2) water pressure and 2200 min/min servo feed rate for the WEDM performance to produce an optimum machining speed and Ra. (C) 2016 Elsevier Ltd and Techna Group S.r.l. All rights reserved.