Characterization of a new copper-based material for harsh rocket environments

During recent years, there has been a growing interest in copper-based materials for structural high-heat-flux applications. This results from two significant developments: the advancement of additive manufacturing (AM) and the positive impact of space exploration. In line with this context, the present work focuses on characterizing a new copper-based material developed via laser powder bed fusion (LPBF). The Italian company SÒPHIA HIGH TECH S.R.L. has patented a powder mixing system known as POWMIX. Using this technology and starting from a powder mixture of 80% pure copper and 20% 17-4PH martensitic stainless steel, it was possible to produce a multiphase material through in situ alloying with LPBF . The material is addressed as Cu17-4PH-8020. The composition has been developed by SÒPHIA HIGH TECH S.R.L. (Naples, Italy) and studied in collaboration with DIMEAS (Dipartimento di Ingegneria Meccanica e Aerospaziale) and DISAT (Dipartimento Scienza Applicata e Tecnologia) of the Polytechnic of Turin. To characterize the material, it was necessary to evaluate the stability of the composition along the entire building platform. To do this, process parameters were taken constant and samples of different positions on the platform were analysed. Moreover, powder sampling was conducted to evaluate the flowability and absorbance level of the mixture. Initially, the density of the massive samples was measured using Archimede’s principle. From this first analysis, the most promising samples were observed with the metallographic optical microscope and a statistical image analysis was carried out. The scanning electron microscope (SEM) was used to analyse the microstructure. With energy dispersive spectroscopy (EDS) the chemical composition was revealed. Mechanical and thermal tests such as microhardness and tensile tests, and thermal conductivity tests were performed. Finally, following the differential scanning calorimetry (DSC) spectrum analysis, a preliminary hypothesis of heat treatment was made.