Yun Bai, PhD Student, Virginia Tech
Christopher Williams PhD, Associate Professor, Virginia Tech
The ability to fabricate geometrically complex copper components via Additive Manufacturing (AM) has a significant impact on the design and performance of thermal management systems and structural electronics. Among metal AM technologies, the Binder Jetting process provides an economical and scalable means of fabricating complex parts from a wide variety of materials; in this work, its feasibility of printing high purity copper components has been demonstrated on ExOne 3D printers. While Binder Jetting is often used to fabricate metal parts, the performance metrics of the resulting sintered parts (e.g., thermal, electrical, and mechanical properties) are typically lower than traditionally manufactured counterparts due to challenges in achieving full theoretical density. This presentation explores the use of modified powder size distributions, Hot Isostatic Pressing (HIP) techniques, and inkjet printing of nanoparticle inks to improve densities in printed and sintered copper. After adopting the new powder compositions and HIP, 99.8% density is achieved in the sintered copper parts. To study the performance metrics in copper parts made in Binder Jetting, thermal and electrical conductivities are measured in the sintered copper parts and correlated to the part porosities.