Design and Fabrication of Random Metal Foam Structures for Laser Powder Bed Fusion

Area of Science:

• Materials Science
• Mechanical Engineering
• Additive Manufacturing

Background:

• Additive manufacturing enables novel lightweight structures like random foams.
• Complex part geometries in additive manufacturing can lead to defects or process failure.
• Design stage interventions are crucial for successful fabrication of intricate structures.

Purpose of the Study:

• To propose a design for additive manufacturing (DfAM) method for creating metal random foam structures.
• To develop a procedure for generating interconnected porosity based on target density and technical requirements.
• To optimize and mesh the geometry for additive manufacturing.

Main Methods:

• A procedure was developed to generate random foam structures with interconnected porosity.
• The design process incorporated aimed fractional density and technical specifications.
• Geometry optimization and meshing were performed.
• A test article was manufactured using laser powder bed fusion (LPBF).

Main Results:

• A metal cylinder with random spherical pores (1-6 mm diameter) and 40 ± 2% fractional density was successfully fabricated.
• The manufacturing process provided crucial data for algorithm refinement.
• The proposed DfAM method facilitates the creation of complex random foam structures.

Conclusions:

• The developed DfAM method is effective for producing metal random foam structures with controlled porosity.
• Validation through LPBF manufacturing confirmed the algorithm's viability and provided insights for improvement.
• This approach addresses challenges in fabricating complex lightweight structures via additive manufacturing.