Oil Removal from Sintered Iron Using Plasma DC Discharge

Abstract

In this work, the viability of the plasma use is demonstrated for the oil removal of metallic pieces sintered at 850°C, compacted at 250, 450 and 600 MPa. The sintered samples of pure iron, stored in oil, were treated in an abnormal glow gas mixture discharge of Ar and H 2 . The electric discharge was generated in a confined anode-cathode configuration, with the samples placed on the anode. The samples were characterized by measures of mass loss, optical microscopy and X-ray diffractometry. The results show that a H 2 discharge at a pressure of 267 Pa for 600 seconds is sufficient to remove the oil from sintered metallic pieces, maintaining temperature at 200°C for pieces compacted at 250 MPa, at 250°C for pieces compacted at 450 MPa and at 300°C for pieces compacted at 600 MPa. Confirming these results, the samples treated under these conditions were submitted to nitriding treatment in the confined cathode-anode configuration and they presented similar results to the ones obtained for samples not stored in oil.