Surface morphology and drilled hole accuracy of conductive ceramic composites Si 3 N 4 -TiN and MoSi 2 -SiC on EDMed surfaces

Abstract

Abstract By using electro-discharge machining (EDM), conductive ceramic composites made of Silicon Nitride and Titanium Nitride (Si3N4-TiN) and intermetallic ceramic composite (MoSi2-SiC) were machined while performance metrics of crucial importance to the EDM process were measured. The two conductive ceramic composites are thoroughly examined using machining parameters including current, spark on time, spark off time, and dielectric pressure. For multiple responses of geometrical errors, such as circularity, cylindricity, and perpendicularity, as well as performance metrics like metal removal rate (MRR), electrode wear rate (EWR), wear ratio, and surface integrity on the machined surface of the workpiece and electrode. Taguchi’s based L9 Orthogonal array (OA) based onthe design of experiments(DOE) is used to carry out the experimental runs to identify the optimum parameters of Si3N4–TiN and MoSi2–SiC ceramic composite. By analyzing the performance of conductive ceramic composites, the optimized results achieved from these approaches are suggested to improve themetal removal rate and lower the tool wear ratio, surface roughness and geometrical tolerances. An elaborated investigation of material removal mechanism and the surface topographyas examined by the SEM instrument with EDAX report in the machined surface for both composites. By analysing the machined surface on the best hole with the best electrode and the worst hole with the worst electrode the surface textures from nine holes and electrodes for ceramic composites are studied. Thus, simultaneously analysed and established EDM process appears to be a promising method for producing excellent surfacesin anelectrically conductive Si3N4–TiN and MoSi2–SiC composite under slow process parameters condition of conductive ceramic composites.