Surface modification of Hastelloy processed by the Cu mixed electric discharge alloying technique

Abstract

An attempt was made in this study to coat Hastelloy with copper carbide utilizing an electric discharge alloying process. Experiments were carried out in such a way that materials were initially removed from the surface, but after a prescribed time in the absence of flushing, it was coated on the surface. Experiments were conducted by varying copper powder concentration, current, pulse on time, and gap distance and experimental runs were designed using the Taguchi mixed orthogonal array. Pure dielectric medium materials were removed from the surface, at 5 g l −1 PMEDM material removal followed by deposition occurred, beyond 10 g l −1 PMEDM condition, only material deposition was observed. Surface topography revealed that the cracks formed on the coated surface with an increase in Cu concentration get intensified and penetrated the base material. The hardness and wear resistance of coated samples are enhanced owing to the presence of harder carbide particles and mechanically mixed layer formation. The mode of wear was adhesive and abrasive for the uncoated and coated samples.

Electric discharge coating process: a critical review with potential application

“…Sugumaran AA et al [110] tested dry sliding wear on Co-Cr plasma-coated Ti alloy implant, and the nitride coating substrate showed high wear resistance and reports lowest wear coefficient of 1.11 × 10-15 m 3 /Nm, through 2 Km of sliding distance. Jayachitra R et al [111] developed a wear-resistance coating on Hastelloy with copper powder suspension, showing that coating thickness increases with powder concentration. Kennedy DM et al [112] explain various wear test methods for coating and suggest a pin-on-disc wear test for EDC process.…”

Enhancing the hydrophobicity of Ti–6Al–4V through multi-level electrical discharge texturing

“…This has been possible due to the exceptional ability of surfaces machined through EDM, which are shielded by a series of coinciding craters [19]. In addition, the creation of a recast film of material over the newly generated surface assists in promoting some desirable characteristics owing to the transfer of material from tool and dielectric in this layer [20,21]. Additionally, endeavours have been developed to deposit the materials on the substrate using the EDM procedure using reverse polarity [22].…”

Surface modification in the shape of a pattern using crepe paper maskant in EDM

“…Similarly, Tyagi et al [10] altered the mild steel surface by mixing powders of hexagonal boron nitride with copper particles. The surface property can also be improved by migrating powder particles suspended into dielectric [11,12]. PM tool enables higher rate of particles migration as compared to solid tool [13].…”