# Grinding-Electrode-Assisted Short Electric Arc Machining of GH4099: A Composite Approach to Surface Integrity

## TL;DR

A new method combining grinding and electric arc machining improves surface quality and efficiency when processing GH4099.

## Contribution

A composite process integrating diamond-coated grinding and SEAM is introduced for enhanced surface integrity in GH4099.

## Key findings

- The composite process achieves stable discharges and uniform textures within a robust voltage and speed range.
- Multi-scale analysis shows reduced recast layers and improved surface quality compared to single-mode SEAM.
- Controllable roughness and efficient debris evacuation are achieved through the erode–dress coupling mechanism.

## Abstract

This study introduces a composite method that integrates a diamond-coated tubular grinding electrode with short electric arc machining (SEAM) for GH4099. Mechanical micro-grinding and arc erosion act concurrently within the inter-electrode gap, enabling an in situ “erode–dress” coupling in which the grinding action levels nascent craters and promotes debris evacuation while SEAM supplies localized thermal–electrical energy for removal. A design-of-experiment scheme probes discharge and grinding factors, and performance is evaluated by material removal behavior, electrode wear, and surface integrity. Within a robust window (12–24 V; 500–2000 r/min), the composite process sustains stable discharges without catastrophic melting at 24 V and yields dense, uniform textures. Representative surfaces show controllable areal roughness (Sa ≈ 14–27 µm across 80#–600#), reflecting a practical finishing–efficiency trade-off. Multi-scale characterization (3D topography, cross-sectional metallography, SEM) evidences suppression of recast steps, macro-protrusions, and irregular pits, with more evenly distributed, shallower grinding traces compared to those with single-mode SEAM. The comparative analyses clarify discharge stabilization and recast-layer mitigation mechanisms, establishing a feasible pathway to high-quality, high-efficiency composite SEAM of GH4099 without resorting to overly aggressive electrical conditions.