PARAMETRIC INVESTIGATION OF WET, NEAR DRY AND DRY EDM ON INCONEL

Abstract

A comparison was to be done between wet, near-dry and dry EDM and also parametric optimization was to be done for the three EDM processes. To perform experiments using dry and near-dry EDM (NDEDM) process. a setup was fabricated. This setup was attached on diesinking EDM. A pilot experimentation was conducted on stainless steel using NDEDM to check the feasibility of the set-up. It was found that the set-up performed its Function satisfactorily. The effect of pulse current (lp), pulse-on time (T0 ) and lift setting on NDEDM of stainless steel was investigated. Taguchi's technique was applied to obtain an optimal setting of the process parameters. The measured results and subsequent analysis revealed that Ii was the only sigiiilicant parameter. MRR increases with an increase in Ip. Also TWR was found to be negligible in comparison of MRR. After confirming the repeatability of the set-up, inconel was drilled using wet, near-dry and dry - NDM ([)FI)M) under the same conditions. The effect of pulse current (Ip), pulse-on time (TO)). pulse-off (ToIT) and gap control setting was investigated for the three EDM processes.. It was found that MRR was highest for NDEDM and TWR was lowest for DEI)M. As TWR was negligible for DE[)M and NDEDM (< 1% of MRR), its analysis was not done. In wet EDM, '1' j) was the most significant factor for MRR and MRR increased with an increase in T. In ND1iDN, contribution of l was highest and MRR increased with increase in l and T. In DEDM also contribution of I was highest and MRR increased with an increase in li,.