Functional Surfaces via Laser Processing in Nickel Acetate Solution

Area of Science:

• Materials Science
• Surface Engineering
• Laser Processing

Background:

• Enhancing surface mechanical properties is crucial for material durability.
• Traditional surface treatments can be limited in achieving subsurface modifications.
• Laser processing offers precise control over material modification.

Purpose of the Study:

• To develop and evaluate a novel laser processing technique in liquid media for C45E steel.
• To investigate the effects of nickel micro-alloying on subsurface properties.
• To enhance the surface mechanical properties and corrosion resistance of C45E steel.

Main Methods:

• Laser processing of C45E steel using a pulsed laser in an aqueous nickel acetate solution (15% wt.).
• Utilizing a robotic arm and a specific optical system for under-liquid micro-processing.
• Analysis of surface morphology, chemical composition, and structural development using optical microscopy, scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction.

Main Results:

• Achieved micro-alloying and phase transformation up to a 30 µm depth.
• Observed microstructure refinement and formation of nickel-rich compounds at the subsurface.
• Significantly improved microhardness (from 250 to 660 HV _0.03) and elastic modulus (230 GPa).
• Demonstrated over 50% improvement in corrosion rate resistance.

Conclusions:

• The novel under-liquid laser processing technique effectively enhances the surface mechanical properties of C45E steel.
• Subsurface nickel micro-alloying is a viable method for improving hardness, elastic modulus, and corrosion resistance.
• This technique offers a promising approach for advanced surface engineering applications.