Microstructure Evolution of TiC Particles In Situ, Synthesized by Laser Cladding

Area of Science:

• Materials Science
• Metallurgy
• Surface Engineering

Background:

• Ti-6Al-4V alloy is a widely used titanium alloy.
• Metal matrix composite coatings enhance surface properties.
• Laser cladding is a key technique for producing advanced coatings.

Purpose of the Study:

• To fabricate TiC reinforcement metal matrix composite coatings on Ti-6Al-4V alloy.
• To investigate the microstructure and phase distribution of the coatings.
• To understand the influence of laser cladding process on TiC morphology.

Main Methods:

• Laser cladding using nickel and graphite mixing powder on Ti-6Al-4V substrate.
• Microstructural characterization using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Energy Dispersive X-ray Spectroscopy (EDS).

Main Results:

• Successful production of TiC reinforced metal matrix composite coatings.
• Predominantly granular TiC phases (several micrometers) observed, with some petal/flake morphologies.
• Special TiC patterns identified in cross-sections, influenced by convection.
• Even distribution of TiC attributed to mass transfer and convection in the laser-melted pool.

Conclusions:

• Laser cladding effectively produces TiC reinforced composite coatings on Ti-6Al-4V.
• Convection within the laser-melted pool plays a crucial role in homogenizing elements and influencing TiC morphology and distribution.
• The lower density of TiC and high convection speeds contribute to its unique patterns and distribution.