Spherulitic growth process in Ti-based metallic glass: Microstructure, phase identification, and growth mechanism

Ti40Cu36Zr10Pd14 metallic glass is often considered a promising candidate for biomedical applications, in particular the manufacturing of small size dental implants. Nevertheless, its processing and limited glass-forming ability leads to appearance crystalline spheres called “spherulites”. These spherulites play major role deformation behaviour this alloy. It therefore critical issue future industrial use identify their nature better understand growth process enable control distribution localisation. This article presents detailed description microstructure these defects, from sub millimetre nanometric scales, using transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS)/electron backscatter diffraction (EBSD) coupled with scanning characterisation. Several phases are identified thanks combination EDS/EBSD TEM information, CuTi B2 phase, analogous ZrCu phase usually present other composite glasses. The presence such as Ti2Cu3 CuTi3 also detected. studied at different times during process, scenario proposed based on characterisation observations. However, nucleation step remains unclear despite in-depth investigation. Thus, hypotheses discussed.