The aerospace industry is constantly looking for innovative materials with high thermal conductivity and high resistance with which to produce liquid rocket engines. In this context, additive manufacturing is widely used: SLM (Selective Laser Melting) is an additive manufacturing technique which processes the parts by melting metallic powders with a laser. Sophia High Tech srl has patented a powder mixing process through which it is possible to obtain an innovative metal-matrix composite starting from copper (65%) and 17-4PH (35%) powders: Cu174PH processable by SLM. The aim of this thesis work is to analyse the effects of heat treatments on properties and microstructure of Cu174PH and to optimizing the best compromise in terms of thermal and mechanical properties.