Analysis of effects of reactant particle size on phase transformations in the Ti-Si-Cu system using differential thermal analysis and x-ray diffraction

摘要

Effects of Ti and Si particle sizes on phase transformations of Ti-Si-Cu system were explored through differential thermal analysis (DTA), x-ray diffraction (XRD), and field emission scanning electron microscope (FESEM). For Ti_([15])Si_([15])Cu_([45]) system, fine Ti easily dissolves into Si-Cu liquid to form Ti-Si-Cu liquid at ~795 ℃, which further participates into the reaction of (3-Ti and Si to yield abundant quantity of Ti_5Si_3 at ~917 ℃. For Ti_([150])Si_([15])Cu_([45]) system, nonetheless, the reaction of coarse Ti with Si-Cu liquid involves more difficulty in forming the ternary liquid , which is the causal factor for the delay in the formation of Ti_5Si_3 to ～948 ℃. For Ti_([15])Si_([150])Cu_([45]) system, coarse Si results in the formation of insufficient Si-Cu liquid initially, whereas Ti-Cu liquid forms at ~960 ℃ instead, which further reacts with coarse Si to form Ti-Si-Cu liquid, and then Ti_5Si_3 is precipitated from the liquid.