Surface Modification of Strenx 900 Steel Using Electrical Discharge Alloying Process with Cu-10Ni- CrxPowder Metallurgy Sintered Electrode

Abstract

The present investigation aims to coat the layer with Nickel (Ni) and Copper (Cu)over the surface of strenx 900 steel using semi sintered Cu-10Ni-Cr x electrodes(x = 2, 4 & 6 wt. %). Three different proportions of semi sintered electrodes such as, Cu-10Ni-2 weight percentage of Chromium (Cr), Cu-10Ni-4 wt. % Cr,and Cu-10Ni-6 wt. % Cr were prepared by powder metallurgy route. Electric discharge alloying was completed based on L 9 orthogonal array and alloyed parameters were optimized using Taguchi method. The alloyed surfaces were characterized using scanning electron microscope and atomic force microscopy. The deposition of formation of intermetallic was studied using X-ray diffractometer. Higher Material Transfer Rate (MTR) was obtained at 9A, 350A and 6% chromium using Cu-10 Ni-Cu electrode. The chromium percentage was the foremost factor on Surface Roughness (SR) (73.71%) and MTR(96.56%). From Taguchi approach, the minimum SR was attained at percentage of chromium of 2%, compaction pressure of 250 Megapascal (MPa) and peak current of 9A. The maximum MTR was achieved at 6 percentage of Cr, compaction pressure of 350 MPa and peak current of 3A. Wear loss for Cu-10 Ni-Cr increases linearly with increase in sliding speed from 2m/s to 4m/s respectively.

A Review of Electrode Manufacturing Methods for Electrical Discharge Machining: Current Status and Future Perspectives for Surface Alloying

“…The study indicated the influence of the tool material on the workpiece, and it was observed that the surface finish was below the acceptable limit, with values exceeding 10 microns. Sridhar et al [154] attempted the electrical discharge modification process using a Cu-10Ni-Cr sintered P/M electrode for the surface modification of Strenx 900 steel. Their study suggested that chromium, copper and nickel were deposited on the workpiece.…”