Manufacturing copper complex parts using an innovative Printing-Debinding-Solar Sintering (PDSS) process

Abstract

Additive manufacturing (AM) makes it possible to produce parts with complex and customized shapes (internal channels or lattice structures), optimizing their physical, mechanical and/or thermal properties. The application of Concentrated Solar Energy (CSE) in an innovative Printing-Debinding-Solar Sintering (PDSS) methodology has been shown to be an effective and efficient way to produce dense copper parts with competitive mechanical, thermal, and electrical performance. The use of CSE in the sintering stage lowers treatment temperatures and shortens manufacturing times thanks to the activator effect of solar radiation in diffusion processes, reducing total costs and environmental footprint. However, further research is required into its application in the fabrication of complex functional metal components. This study addresses the design of a heat sink and a cylindrical catalyst for the first time, as well as its manufacturing via the PDSS methodology, establishing the optimal processing parameters and evaluating the properties of the final parts. Density measurements, scanning electron microscopy and computed tomography analysis were carried out at the different stages of the processing in order to evaluate the porosity and properties of as-printed, washed, brown and final parts. Complex geometry copper parts were successfully manufactured using a PDSS technique in shorter times (1 h) and with lower sintering temperatures (950 °C) than those required by conventional electric furnaces (∼25 h, 1075 °C), improving the sustainability and technical applications of this methodology. Furthermore, solar sintered copper components achieved competitive relative density properties up to ≈95 %, as well as adequate dimensional accuracy and deviation.