Tribological Characterization of Electrical Discharge Machined Surfaces for AISI 304L

Area of Science:

• Materials Science
• Mechanical Engineering
• Surface Engineering

Background:

• Surface treatments are often necessary after machining, adding significant cost and time.
• Electrical Discharge Machining (EDM) creates a recast layer on components, whose tribological properties are not fully understood.
• The characteristics of the EDM recast layer are influenced by discharge current, electrode material, and dielectric fluid.

Purpose of the Study:

• To investigate the impact of EDM parameters (discharge current, electrodes, dielectrics) on the tribological performance of recast layers.
• To analyze wear depth, friction coefficient, friction force, and contact surface temperature.
• To determine if tribological properties can be controlled by adjusting EDM process variables.

Main Methods:

• Utilized Electrical Discharge Machining (EDM) to create recast layers on AISI 304L stainless steel.
• Conducted tribo-tests using a pin-on-disc configuration in the boundary lubrication regime.
• Employed Scanning Electron Microscopy (SEM) for surface morphology analysis before and after tribological testing.

Main Results:

• Demonstrated that varying EDM parameters significantly influences the tribological performance of the recast layer.
• Identified specific combinations of discharge current, electrodes, and dielectrics that enhance desirable surface properties.
• Quantified changes in wear depth, friction coefficient, friction force, and surface temperature based on parameter adjustments.

Conclusions:

• It is feasible to tailor the tribological characteristics of EDM-generated recast layers by manipulating EDM process parameters.
• This optimization approach offers a method to enhance surface quality and reduce post-machining treatment costs and time.
• Controlling recast layer properties directly through EDM presents a cost-effective alternative to conventional surface treatments.