Laser Powder Bed Fusion Processing of Ti-6Al-4V Powders with Offsize and Wide Particle Size Distributions-Process...

Area of Science:

• Materials Science
• Additive Manufacturing
• Powder Metallurgy

Background:

• High cost of raw materials hinders metal additive manufacturing (AM) adoption.
• Laser powder bed fusion (LPBF) is a key AM technology.
• Ti-6Al-4V is a widely used titanium alloy in AM.

Purpose of the Study:

• Optimize LPBF process parameters for cost-effective Ti-6Al-4V powders with offsize (45-106 µm) and wide (15-106 µm) particle size distributions (PSD).
• Compare performance using these powders against standard (15-53 µm) PSD.
• Establish correlations between LPBF parameters and resulting density, hardness, and roughness.

Main Methods:

• Multi-step experimental design and optimization.
• Investigated process parameter impact using the contour-skin-core method.
• Analyzed porosity, microstructure, elemental composition, and dimensional fidelity of components.
• Utilized optimized parameters for density to assess other properties.

Main Results:

• Achieved 98.7% density and 40.6 HRC hardness for offsize powder; 98.7% density and 40 HRC hardness for wide powder.
• Optimized parameters for larger geometries yielded >99.9% density (as-built and HIP).
• Roughness sensitivity to powder size confirmed (9.5–15.7 µm).
• No significant microstructural differences observed between powder types.

Conclusions:

• Utilizing cost-effective Ti-6Al-4V powders with larger particle sizes is viable for LPBF.
• This approach can mitigate costs associated with metal additive manufacturing.
• Optimized parameters enable high-density components with acceptable mechanical properties.