<p>In response to challenges posed by conventional machining methods, an exploratory experimental investigation was conducted to assess the effectiveness of wire electric discharge machining (WEDM) in fabricating turbine disc slots from powder metallurgy superalloy FGH99. The present study conducted a single-factor experiment on WEDM using FGH99 alloys, with the aim of investigating the impact of different WEDM parameters on the material removal rate, surface roughness, and surface morphology. Additionally, the analysis encompassed the characterization of both the heat-affected zone and plastic deformation zone on the workpiece surface. Results show that there is a positive correlation between surface roughness and variables such as pulse width, pulse gap, servo voltage, and wire tension. For instance, when the pulse width is augmented from 3 to 7 μs, the surface roughness (<i>R</i>_a) escalates from 1.87 to 2.98 μm. Similarly, the enhancement of the pulse gap from 10 to 30 μs results in an increase in surface roughness from 2.02 to 2.33 μm. Conversely, wire speed exhibits an inverse relationship with surface roughness. For example, when the wire speed is increased from 40 to 120 mm/min, the surface roughness decreases from 2.13 to 1.94 μm. Notably, the impact of pulse width on surface roughness surpasses that of other parameters. Metallographic examination reveals that under the selected process parameters, while ensuring the efficiency of material removal, superior machining quality was achieved. The absence of conspicuous recast layers on the workpiece surface, with an average thickness of the plastic deformation layer measured at 3.97 μm, indicating favorable processing outcomes. The aforementioned findings provide valuable experimental insights into the WEDM process of FGH99 alloys and offer foundational engineering data for the fabrication of turbine disc slots made from this material.</p>