Mechanism and kinetics of the intermediary phase formation in Ti-Al and Ti-Al-Si systems during reactive sintering

摘要

In this work, chemical reactions and phase transformations during reactive sintering of Ti-Al and Ti-Al-Si materials were investigated by differential thermal analysis. Kinetics and mechanism of the formation of intermediary phases are described on an experimental model system consisting of a bulk titanium sample exposed to molten aluminium or AlSi50 alloy. The results show that the reactive sintering is a reaction-controlled process in both systems. The reaction rate increases significantly with addition of silicon. According to the kinetics study, reactive sintering of TiAl36 and TiAl15Si15 alloys was carried out. TiAl15Si15 alloy was successfully sintered, while TiAl36 material showed extremely high porosity and presence of unreacted components.