Localized Pulsed Electrodeposition Process for Three-Dimensional Printing of Nanotwinned Metallic Nanostructures

Area of Science:

• Materials Science
• Nanotechnology
• Additive Manufacturing

Background:

• Nanotwinned metals (nt-metals) exhibit enhanced mechanical and electrical properties over nanocrystalline (nc) counterparts.
• Current fabrication methods for nt-metals are limited to 2D films or 1D template-based structures.
• These limitations hinder the application of nt-metals in 3D nanoscale devices.

Purpose of the Study:

• To demonstrate a novel method for fabricating freestanding three-dimensional (3D) nanotwinned-copper (nt-Cu) nanostructures.
• To characterize the microstructure and mechanical properties of the 3D-printed nt-Cu.
• To compare the properties of 3D-printed nt-Cu with 3D-printed nc-Cu.

Main Methods:

• Ambient environment localized pulsed electrodeposition for direct printing of 3D nt-Cu.
• Additive manufacturing using pulsed electrodeposition at the tip of an electrolyte-containing nozzle.
• Focused ion beam (FIB), transmission electron microscopy (TEM), and in situ scanning electron microscopy (SEM) microcompression for analysis.

Main Results:

• Successfully fabricated freestanding 3D nt-Cu nanostructures via pulsed electrodeposition.
• Analysis confirmed a fully dense microstructure with coherent twin boundaries and minimal defects.
• The 3D-printed nt-Cu achieved a flow stress exceeding 960 MPa, significantly higher than nc-Cu printed under DC voltage.

Conclusions:

• The developed pulsed electrodeposition technique enables the direct 3D printing of freestanding nt-Cu nanostructures.
• The 3D-printed nt-Cu exhibits exceptional mechanical strength, surpassing previously reported values for 3D-printed materials.
• This advancement opens new possibilities for utilizing nt-metals in demanding 3D nanoscale device applications.