Experimental characterization of a new L-PBF AM 65% copper - 35% maraging steel metal-matrix-composite for liquid rocket engine thrust chambers

Thrust chamber, in high performance bi-propellant liquid rocket engines, is a critical component of the launch vehicles as it is designed to operate in some of the most severe conditions. The requirement of reducing the temperature of the walls exposed to the hot gases can be met with high-thermal conductivity copper alloys, while the mechanical resistance is achieved by using high-strength nickel alloys. Because the mechanical behavior of a regeneratively cooled thrust chamber is related to its temperature behavior, it is of primary importance to select the correct alloy. A new copper-steel matrix composite for liquid rocket engine application, processed by Laser Powder Bed Fusion (L-PBF) Additive Manufacturing process, is proposed. The realization of such composite is based on an innovative process of mixing copper and steel powders. A detailed thermal and mechanical characterization of the composite is investigated. The composite shows a consistent overall mechanical behavior. Although the yield strength is higher than that of common copper-based alloys used in liquid propellant rocket engines, the thermal conductivity is significantly lower. Therefore, optimization of process parameters will be required to improve thermal properties in order to propose this new material as a candidate for future liquid rocket engine thrust chambers.