Understanding the effects of PBF process parameter interplay on Ti-6Al-4V surface properties

Area of Science:

• Biomaterials Engineering
• Additive Manufacturing
• Surface Science

Background:

• Titanium alloy (Ti-6Al-4V) is crucial for orthopaedic implants.
• Powder Bed Fusion (PBF) enables complex, customized implant fabrication with reduced waste.
• Current research often focuses on design or mechanical properties, neglecting bioactivity tuning during fabrication.

Purpose of the Study:

• To investigate the impact of varying PBF process parameters on Ti-6Al-4V microstructure, mechanical properties, and surface characteristics.
• To understand how to optimize Ti-6Al-4V bioactivity directly during the PBF fabrication stage.
• To evaluate the relationship between PBF parameters and Ti-6Al-4V bioactivity-related properties.

Main Methods:

• Systematic variation of PBF laser scan speeds and laser powers.
• Analysis of resulting changes in Ti-6Al-4V hardness, porosity, and surface roughness.
• Assessment of Ti-6Al-4V corrosion resistance through electrochemical behavior analysis.
• Examination of surface characteristics across a wide range of process parameters.

Main Results:

• The interplay of laser scan speed and power significantly influences Ti-6Al-4V hardness, porosity, and roughness.
• Volumetric Energy Density (VED) is an inadequate predictor of PBF Ti-6Al-4V properties.
• A wide spectrum of porosity (0.03% to 32.59%) and corrosion resistance is achievable via minor PBF parameter adjustments.
• Electrochemical behavior and surface characteristics vary considerably with PBF process parameters.

Conclusions:

• PBF process parameters have a complex, non-linear effect on Ti-6Al-4V properties relevant to bioactivity.
• Optimizing bioactivity requires careful control of PBF parameters beyond simple VED calculations.
• This study provides crucial data on surface characteristics over an extensive process window, enhancing PBF capabilities for implant fabrication.