Design and Performance of Property Gradient Ternary Nitride Coating Based on Process Control

Area of Science:

• Materials Science
• Surface Engineering
• Tribology

Background:

• Surface coatings enhance cutting tool performance, with multi-layered and gradient structures being common strategies.
• Interface composition mutations in multi-layered coatings degrade overall performance, necessitating interface effect mitigation.

Purpose of the Study:

• To propose a structure design method for property-component gradient coatings using process control.
• To develop ZrTiN gradient coatings with high internal cohesion and external hardness to minimize interface issues.
• To evaluate the mechanical properties, friction, and cutting performance of the gradient coating against a single-layer coating.

Main Methods:

• Depositing a ZrTiN property gradient ternary nitride coating on cemented carbide via multi-arc ion plating using separated Ti and Zr targets.
• Systematically investigating mechanical properties, friction behaviors, and cutting performances.
• Comparing the gradient coating's performance with a standard single-layer coating.

Main Results:

• The gradient coating exhibited superior friction and wear performance, characterized by a lower wear rate and increased resistance to peeling during sliding friction.
• Gradient-structured coatings demonstrated enhanced wear and damage resistance during cutting, resulting in a lower machined surface roughness (Ra).
• The gradient structure effectively inhibited microcrack initiation and propagation under cyclic mechanical and thermal loads.

Conclusions:

• The proposed process control method enables the fabrication of property-component gradient coatings with reduced interface mutations.
• ZrTiN gradient coatings offer significant improvements in tribological and cutting performance compared to single-layer coatings.
• This approach is extendable to other ternary nitride coatings, offering a pathway for advanced surface engineering.