Effect of Ti-Si3N4 system on microstructure of TiN-Ti5Si3 reinforced Cu matrix composites

In this work, the influence mechanism of the initial state of Ti-Si3N4 system on the prepared composites was explored, and the treatment which changes the size of Si3N4 and ball-milled Ti-Si3N4 system was carried out. It is found that the large Si3N4 particles (20 and 50 mm) tend to form more core-shell particles in the composite, and the synthesized TiN particles tend to aggregate around core-shell particles. When the size is small (2 mm), Si3N4 tends to bind to each other, and the TiN will grow synergically and connect to form aggregations. However, the distribution of TiN can be improved by ball-milling Ti-Si3N4 powders for an appropriate time, and the dispersion of the enhanced phase will be more difficult when the optimal ball-milling time is exceeded. It is proved that in the vacuum environment, where the ball-to-weight is 6:1 and the milling speed is 300 rpm, ball-milling for Ti-Si3N4 mixed powder with 6 h can effectively promote the uniformity of microstructure of the prepared TiN-Ti5Si3 reinforced Cu matrix composites.(c) 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

This work investigates the influence of the initial state of Ti-Si3N4 system on the prepared composites. It is discovered that the size of Si3N4 particles affects the formation of core-shell particles and the aggregation of TiN particles. Furthermore, ball-milling Ti-Si3N4 powders can improve the distribution of TiN, but excessive ball-milling time hinders the dispersion of the enhanced phase. The study demonstrates that ball-milling Ti-Si3N4 mixed powder for 6 hours in a vacuum environment with a ball-to-weight ratio of 6:1 and a milling speed of 300 rpm effectively promotes the uniformity of the microstructure of the TiN-Ti5Si3 reinforced Cu matrix composites.