Optimization of Surface Integrity of Titanium-Aluminum Intermetallic Composite Machined by Wire EDM

This study investigate the influence of the machining parameters on Ti-Al intermetallic composite based using a wire electrical discharge machining. This process is typically used for very hard material, which are hard to machine using a more traditional process. The aim of the work is to optimize the integrity of surface of Ti-Al intermetallic composite machined by WEDM. The first step is defined the machining parameters of the process: Start up voltage U, Pulse on time Ton or T, advanced speed S and flushing pressure P (pressure of injection of dielectric) are chosen to determine their effects on surface roughness Ra. The second step is using integrated method, which mixed Taguchi method and response surface methodology RSM, the RSM model was developed as a tool to predict the integrity of surface of Ti-Al intermetallic composite machined by WEDM. The significance of the machining parameters was obtained using analysis of variance (ANOVA) based on S/N ratio, which show that flushing pressure P, Pulse on Time T and Voltage U were the most significant parameters. Microstructure of surface and subsurface, cracks, craters, and debris and roughness surface of the samples machined at the different condition has been realized by scanning electron microscopy (SEM), and 3D-Surfscan. The integrate method of Taguchi and RSM was validated by conducting validation experiment to ensure that it can work accurately as a prediction tool.