Manufacturing High-Conductivity Copper with AM

The Challenge

Pure copper’s exceptional electrical and thermal conductivity makes it essential for electrical components, heat exchangers, and electromagnetic applications. Additive manufacturing of copper must solve three problems at once: achieving full density without residual porosity, maintaining high purity during processing, and verifying that printed parts deliver the conductivity the material promises. Traditional destructive testing consumes valuable prototypes and slows the iterative optimization that AM process development demands.

The Solution

This research developed a complete processing route for 3D micro-extrusion of copper, from feedstock paste formulation through thermal post-processing. The team optimized a propanol-based paste with 95 wt% copper powder loading, then systematically refined printing parameters and sintering conditions to achieve 96–99% dense components.

Impulse excitation testing provided the rapid, non-destructive feedback loop essential for this optimization work. By measuring elastic modulus on each iteration of printed parts, researchers could assess density and structural integrity without sacrificing samples. The correlation between elastic modulus and density gave immediate insight into how changes in paste formulation, extrusion parameters, or sintering conditions affected the final part quality.

Results

The optimized process produces copper parts with electrical conductivity of 90–100% IACS, approaching the theoretical maximum for pure copper. Mechanical properties (yield strength 61 MPa, ultimate tensile 194 MPa, 32% elongation) confirm sound metallurgical bonding. For manufacturers developing copper AM applications, this work demonstrates how IET enables the rapid process iteration needed to achieve both conductivity and mechanical performance targets.

Key takeaway: Paste-based 3D micro-extrusion produced 96-99% dense copper parts with 90-100% IACS electrical conductivity, matching wrought copper performance through AM.