| 摘要 |
<p>In present work, a comparative experimental study has been presented on rough cut, trim cut using distilled water and trim cut using Al and Si metal powders in dielectric fluid for WEDM of Nimonic-90. Firstly, the influence of discharge energy in rough cut has been evaluated for machining rate (MR) and surface roughness (SR) and then, compared with trim cut without any metal powder additives in dielectric fluid. The influence of Al and Si metal powders (varying concentration of 1g/L, 2g/L and 3g/L) in dielectric fluid has been evaluated separately and compared for MR, SR, recast layer and micro hardness of machined Nimonic-90. Using trim cut, a fine and uniform surface texture was obtained irrespective of the high discharge energy of rough cut. Addition of Al and Si powders shows a significant reduction in MR for trim cutting operation whereas a remarkable modification has been obtained in surface textures after trim cut using metal powder mixed dielectric. SR improves with a concentration of 1g/L and then shows a little increase with high concentration of both metal powders. Using metal powder in dielectric fluid, the recast layer becomes smooth and denser and thus, micro hardness increases.</p> |
