Enhancing Tribological Characteristics of Titanium Grade-5 Alloy through HVOF Thermal-Sprayed WC-Co Nano Coatings by...

Area of Science:

• Materials Science
• Surface Engineering
• Tribology

Background:

• Thermal spray coatings are crucial for enhancing wear and tribological properties of metallic substrates.
• Titanium Grade-5 alloy (Ti64) is a widely used material in demanding engineering applications.

Purpose of the Study:

• To develop and optimize High-Velocity Oxygen Fuel (HVOF) sprayed WC-Co nanocoatings on Ti64 alloy.
• To systematically investigate the effect of HVOF process parameters on coating performance.

Main Methods:

• Optimized HVOF spraying parameters including carrier gas flow rate, powder feed rate, and nozzle distance.
• Evaluated wear loss (WL), friction coefficient (CoF), and frictional force (FF) using Pin-on-Disc (PoD) tests.
• Utilized Technique for Order Preference by Similarity to the Ideal Solution (TOPSIS) and golden jack optimization algorithm (GJOA) for response optimization.

Main Results:

• Increased carrier gas and powder feed rates led to higher WL, CoF, and FF.
• Increased spraying distance resulted in lower WL, CoF, and FF due to improved bonding and wear resistance.
• Optimal parameters identified: 245 mm spray distance, 30 gpm powder feed rate, 11 lpm carrier gas flow rate.
• Powder feed rate was the most significant factor (88.99%) influencing the outcome, as per ANOVA.

Conclusions:

• Optimized HVOF spraying of WC-Co nanocoatings substantially improved Ti64 alloy's wear resistance.
• Confirmation experiments showed significant reductions in WL (42.33%), CoF (27.97%), and FF (9.38%) compared to the experimental mean.
• The enhanced durability of Ti64 alloy via HVOF WC-Co nanocoatings offers potential for diverse, high-performance engineering applications.