The Microstructures Of The Tin-Ti5si3 Hybrid Reinforced Cu Matrix Composites Fabricated By The Ti-Si3n4 Reaction And Its Preparation Mechanism

An innovative method for the preparation of TiNeTi5Si3 hybrid reinforced copper matrix composites by the reaction and spontaneous dispersion of TieSi(3)N(4) mixture in Cu melts is proposed in this study. The microstructures of the composites and the reaction process of Ti and Si3N4 with different sizes in Cu melts were analyzed. It is found that the Si3N4 with small size, such as 2 mm, can easily react completely with Ti to form TiN and Ti5Si3. The formed TiN are particle-like and their size ranges from 0.5 mm to 3 mm, while Ti5Si3 are rodlike with a certain length to diameter ratio. In addition, many Ti5Si3 rods are combined with Cu cores to form coreeshell structure. It is considered that these microstructure characteristics are helpful for TiN and Ti5Si3 to form a good hybrid enhancement effect. Although the Si3N4 with large size, such as 50 mm, can also be effectively added into Cu melts by Ti eSi(3)N(4) reaction. However, unlike the composite prepared by 2 mm Si3N4, besides the forming TiN and Ti5Si3, there are other kinds of coreeshell particles present in the matrix, including Si3N4@TiN, Cu@TiN and Si3N4@TiN@Cu@TiN. (C) 2021 The Authors. Published by Elsevier B.V.