Preparation of TiN-Ti5Si3 in-situ composites by Selective Laser Melting

The Selective Laser Melting (SLM) Rapid Manufacturing (RM) of the high-energy ball milled Ti-Si3N4 composite powder with the mol ratio of 9:1 was performed in the present work. The microstructural characterizations revealed the formation of TiN reinforced Ti5Si3 matrix composites after laser processing via the in-situ synthesis reaction 9Ti+Si3N4=4TiN+Ti5Si3. The in-situ presented TiN reinforcing phase possessed a refined granular morphology and a uniform distribution throughout the Ti5Si3 matrix, showing a clear and compatible interfacial structure with the matrix. The metallurgical mechanisms for the in-situ synthesis of TiN reinforced Ti5Si3 matrix composites by SLM were also proposed.