Mechanical Behavior of Titanium Based Metal Matrix Composites Reinforced with TiC or TiB Particles under Quasi-Static...

Area of Science:

• Materials Science
• Mechanical Engineering
• Metallurgy

Background:

• Titanium alloys are crucial in demanding applications, but their behavior under dynamic conditions is understudied.
• Existing data gaps necessitate a
• strength margin
• approach for dynamic performance assurance.
• Understanding high strain rate behavior is vital for designing robust titanium components.

Purpose of the Study:

• To characterize the dynamic mechanical behavior of titanium matrix composites (TMCs) under high strain rates.
• To evaluate the influence of reinforcing particles (TiC and TiB) on TMC performance.
• To provide critical data for avoiding conservative design margins in dynamic applications.

Main Methods:

• Titanium matrix composites (TMMC) were fabricated using Blended Elemental Powder Metallurgy with varying TiC (5-20%) or TiB (5-10%) content.
• High strain rate compression tests (~1-3 × 10³·s^-1) were conducted using the split Hopkinson pressure bar.
• Mechanical behavior was analyzed concerning strain rate, phase composition, microstructure, and strain energy (SE).

Main Results:

• Titanium carbide (TiC) reinforced MMCs (5% TiC) exhibited significantly higher strength and strain energy (SE) than the base alloy up to 1920 s^-1.
• TiC particles localized plastic deformation, leading to fracture via particle crushing.
• Titanium diboride (TiB) MMCs showed finer grains and improved toughness, with 5% and 10% TiB composites remaining intact up to ~3000 s^-1.
• 10% TiB MMC demonstrated superior SE at strain rates above 2200 s^-1.

Conclusions:

• Titanium matrix composites (TMCs) offer enhanced mechanical properties under dynamic loading compared to unreinforced alloys.
• TiC reinforcement improves strength and SE, while TiB reinforcement enhances toughness and high strain rate stability.
• The study provides crucial data for optimizing TMC design for high-strain-rate applications.