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Updated: Jun 12, 2025
Indirect Fabrication of Lattice Metals with Thin Sections Using Centrifugal Casting
Published on: May 14, 2016
Feature size specific processing parameters for additively manufactured Ti-6Al-4V micro-strut lattices
C O'Keeffe1, W Zhang2, R D Johnston1
1Trinity Centre for Biomedical Engineering, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland; Department of Mechanical, Manufacturing and Biomedical Engineering, School of Engineering, Trinity College Dublin, Dublin, Ireland; AMBER, The SFI Research Centre for Advanced Materials and Bioengineering Research, Ireland.
Optimizing powder bed fusion parameters for micro-struts requires higher energy density due to heat loss. This improves mechanical properties by reducing defects and stress concentrations, but fatigue is limited by surface defects.
Area of Science:
- Materials Science
- Mechanical Engineering
- Additive Manufacturing
Background:
- Lattice structures are critical in biomedical implants, but their performance depends on micro-strut material properties.
- Defects from powder bed fusion (PBF), like porous inclusions, compromise mechanical integrity and implant safety.
- A size effect exists, where defect frequency changes with feature size, necessitating tailored PBF parameters for micro-struts versus bulk components.
Purpose of the Study:
- To investigate the relationship between parameter optimization and feature size in PBF-processed micro-struts.
- To determine optimal energy density for micro-strut lattices to achieve desired relative density.
- To assess the impact of optimized parameters on the mechanical and fatigue properties of micro-struts.
Main Methods:
- Investigated parameter optimization for micro-strut lattices with varying feature sizes.
- Utilized higher energy density for micro-strut processing compared to bulk components.
- Assessed mechanical properties (strength, stiffness, failure strain) and fatigue behavior.
Main Results:
- Higher energy density was required for micro-strut lattices to achieve optimal relative density, attributed to increased heat loss.
- Optimized parameters significantly improved strength and stiffness by increasing load-bearing material volume.
- Improvements in failure strain resulted from minimized stress concentrations around pore morphologies.
- Fatigue properties did not surpass yielding effects, with crack initiation dominated by surface defects.
Conclusions:
- Tailoring PBF parameters, specifically increasing energy density, is crucial for optimizing micro-strut lattices.
- Optimized micro-struts exhibit enhanced strength and stiffness, but fatigue performance remains limited by surface defect severity.
- Understanding the interplay between feature size, processing parameters, and defect formation is key for reliable additively manufactured lattice structures.
