Recrystallization and deformation mechanisms of network-structured TiBw/(TA15-Si) composite

This research explored the hot deformation behavior of TiBw/(TA15-Si) composite with a network structure fabricated by hot pressing sintering. Hot compression test was conducted at 1 000–1 020 °C under strain rate of 1–0.001 s⁻¹. The microstructure evolution and deformation mechanisms were revealed through parent phase reconstruction. During the deformation, Dynamic Recrystallization (DRX) was preferentially developed in TiBw rich region due to the TiBw supplying dislocation pile-up and heterogeneous nucleation sites. The main DRX mechanisms included continuous and discontinuous DRX. The microstructure in TiBw lean region was closely related to strain rates, which was deformed microstructure at high strain rates but DRXed microstructure at low strain rates. The primary mechanisms of deformation were governed by dislocation motion. Besides, in TiBw rich region, Grain Boundary Sliding (GBS) coordinated the deformation due to DRX. However, GBS was hindered again at low strain rates due to the increase of DRXed grain size, contributing to a gradual rise in flow stress.