An In situ neutron diffraction study of phase formation during Ti–Si3N4 powder sintering

Abstract

This paper characterises and evaluates Si3N4/Ti composites during thermal treatment using an in situ neutron diffraction technique. The composites were developed using a conventional press and sinter technique. Pure titanium (Ti) was chosen as the matrix, and different concentrations of Si3N4 were used as the reinforcement. The effects of sintering temperature and the concentration of Si3N4 in the Ti matrix were investigated with respect to phase constituents. The Si3N4 mass fraction in the Ti matrix was found to be the key parameter for the reaction. Because of its instability in Ti at higher temperatures, in situ reactions between the reinforcing particles and matrix led to the formation of intermetallic compounds, such as Ti5Si3 and possibly Ti3Si, in the composites containing higher weight fractions of Si3N4.

Keywords

• Titanium
• Neutron diffraction
• Sintering
• Ti composite
• Phase formation