An exploration of binder jetting of copper

TLDR

Fabricating geometrically complex copper shapes could transform the design and manufacture of components for thermal management systems and structural electronics. This study explores binder jetting to fabricate high‑purity copper parts, demonstrates its first use, and aims to improve densification for better thermal, electrical, and mechanical properties. The authors employed a material‑development workflow, varying powder size and sintering cycles in binder jetting to evaluate their impact on densification. Printing three copper powders and sintering them produced 85 % dense, 97 % pure parts, with 15‑µm powder and a 1,080 °C cycle yielding the best results, though full density remains difficult and further optimization is needed.

Abstract

Purpose – The purpose of this paper is to explore the use of binder jetting to fabricate high-purity copper parts. The ability to fabricate geometrically complex copper shapes would have implications on the design and manufacture of components for thermal management systems and structural electronics. Design/methodology/approach – To explore the feasibility of processing copper via binder jetting, the authors followed an established material development process that encompasses powder selection and tuning process parameters in printing and thermal cycles. Specifically, the authors varied powder size and sintering cycles to explore their effects on densification. Findings – Three differently sized copper powders were successfully printed, followed by sintering in a reducing atmosphere. It was found that a 15-μm-diameter powder with a sintering cycle featuring a 1,080°C maximum temperature provides the most dense (85 per cent) and pure (97 per cent) final copper parts of the parameters tested. Research limitations/implications – Due to powder-based additive manufacturing techniques’ inherent limitations in powder packing and particle size diameter, there are difficulties in creating fully dense copper parts. To improve thermal, electrical and mechanical properties, future work will focus on improving densification. Originality/value – The paper demonstrates the first use of binder jetting to fabricate copper artifacts. The resulting copper parts are denser than what is typically found in binder jetting of metal powders (without infiltration); significant opportunity remains to further optimize the manufacturing process by introducing novel techniques to tailor the material properties for thermal/electrical applications.