الفهرس | Only 14 pages are availabe for public view |
Abstract In this investigation, an experimental study in cylindrical wire EDM machining parameters is presented for both longitudinal and cross-feed turning processes. At first, the design of a precise, flexible and corrosion resistant rotary spindle is introduced. The spindle has been mounted on a conventional four axis wire EDM machine to provide the workpiece rotation in order to generate free form cylindrical geometries. Several experiments are conducted to investigate the influence of six input variables: the depth of cut, gap, workpiece rotational speed, pulse time-on, wire speed and interval time (factors) on the material removal rate (MRR) and the average surface roughness (𝑅𝑎) (responses) as indicators of the efficiency and cost-effectiveness of the process. In this investigation, two techniques for design of experiments (DOE) were used. Stainless steel k316 is one of the difficult-to-machine material, was used in this study. The experimental work was done for longitudinal turning operation by changing one variable and keeping the others constant to point out the effect of each of these variables on the six control factors. In the pre-experiment, regression equations interpreting the relationship between the six input variables and the material removal rate, surface roughness have been deduced. An L18 (21×35) Taguchi standard orthogonal array is chosen for the design of experiments (DOE) for cross-feed turning process due to the number of factors and their levels in the investigation. Mini tab Software version 16 was used to determine the main effects of the process parameters. Analysis of variance (ANOVA) was performed to find the dependent variables that affect the machining characteristics. Regression analysis is performed to find out the relationship between the different factors and responses. Signal to noise (S/N) ratio analysis is used to establish the optimum condition. Key words WEDM, CWEDM, MRR, Ra, Taguchi’s L-18 Orthogonal array |