A Novel Treatment to Selectively Harden Ti6Al4V Surfaces

Area of Science:

• Materials Science
• Surface Engineering
• Tribology

Background:

• Titanium alloys require surface treatments to enhance tribological properties.
• Selective surface hardening is crucial for specific component applications, avoiding bulk treatment.
• Existing methods may not offer efficient selective hardening for titanium.

Purpose of the Study:

• To develop a duplex heat treatment for selective surface hardening of titanium alloys.
• To investigate the use of titanium dioxide (TiO2) powders as an oxygen reservoir.
• To evaluate the impact of the treatment on surface hardness, load-bearing capacity, and tribological performance.

Main Methods:

• A duplex heat treatment combining selective surface prepainting with TiO2 powders and thermal oxidation.
• Diffusion treatment at elevated temperatures (800-900 °C) utilizing the TiO2 layer as an oxygen source.
• Evaluation of hardened surface case depth, load-bearing capacity, and tribological properties.

Main Results:

• The TiO2 powder layer effectively acts as an oxygen reservoir, accelerating diffusion and deep surface hardening.
• The duplex treatment resulted in selectively hardened surfaces with significantly improved tribological properties.
• Optimized treatment demonstrated enhanced load-bearing capacity in the hardened regions.

Conclusions:

• The developed duplex heat treatment enables efficient selective surface hardening of titanium alloys.
• Pre-painting with TiO2 powders is a simple and effective method for industrial application.
• This technique offers a promising approach for enhancing the performance of titanium components in demanding environments.