Thermo-structural analysis and associated experimental characterization of an innovative metal-matrix-composite copper-steel material for a new Liquid Rocket Engine (LRE) thrust chamber geometry processed by SLM Additive Manufacturing

Thrust chamber of high performance bi-propellant liquid rocket engines is a critical component of the launch vehicles because it is designed to operate in some of the most severe conditions seen in engineering practice. The requirement of reducing the temperature of the walls exposed to the hot gas can be met with high-thermal-conductivity copper alloys while the mechanical stiffness is achieved by using high-strength steel or nickel alloys. Because the stress–strain behaviour of a regeneratively cooled thrust chamber is directly correlated with its temperature behaviour, it is of primary importance to select the correct alloy. Nowadays manufacturing processes are playing an important role in the global space industry, with particular emphasis respect to space propulsion. Thanks to Sophia High Tech s.r.l. advanced studies a new patented copper-steel alloy, processed by SLM Additive Manufacturing process, is proposed for a Liquid Rocket Engine (LRE) application. A patented additive manufacturing powders mixing process developed by Sophia High Tech srl is used: it consists in a powder mixing new technology developed in order to mix two or more additive manufacturing powders. A deep thermal and mechanical characterization of the new alloy is presented, with particular reference to high temperature Low Cycle Fatigue, Cp, thermal conductivity, micrography analysis, digital tomography analysis, DRX, thermomechanical analysis TMA) test. A Numerical Non-linear Thermo-Structural Analysis of a new cooling channels geometry is carried out using the commercial software Ansys Workbench in order to improve life and performances of a generic LRE thrust chamber. A The computations are made considering a properly calibrated non-linear kinematic hardening model in order to introduce the correct new alloy’s behaviour.