Metals by Micro-Scale Additive Manufacturing: Comparison of Microstructure and Mechanical Properties

Area of Science:

• Materials Science
• Mechanical Engineering
• Microfabrication

Background:

• Microscale engineering requires 3D inorganic material architectures.
• Small-scale additive manufacturing (AM) offers flexible fabrication but faces challenges in synthesizing device-grade materials.
• Current AM methods with high spatial resolution (≤10 μm) are crucial for microfabrication.

Purpose of the Study:

• To comprehensively review the microstructural and mechanical properties of metals fabricated by state-of-the-art microscale AM methods.
• To establish a baseline for optimizing the properties of additively manufactured metallic objects at the microscale.
• To provide practical guidelines for users of small-scale additive manufacturing techniques.

Main Methods:

• Fabrication of standardized metal samples using microscale additive manufacturing (AM) techniques with spatial resolution ≤10 μm.
• Cross-sectional electron microscopy for microstructural analysis.
• Nanoindentation and microcompression testing for evaluating elastic and plastic mechanical properties.

Main Results:

• Microscale AM techniques produce metals with a wide spectrum of microstructures and mechanical properties.
• Dense, crystalline microstructures exhibiting excellent mechanical properties, comparable to thin-film nanocrystalline materials, were achieved.
• Variations in material performance are directly linked to microstructural differences, which are influenced by the specific AM method's principles.

Conclusions:

• Microscale AM enables the fabrication of metallic materials with diverse properties suitable for microscale engineering applications.
• The study provides essential data and guidelines for selecting and optimizing AM processes for microfabrication.
• This work represents a significant step towards establishing AM as a viable technique for microfabrication of metallic components.