Solidification behaviour of undercooled Nd-Fe-B-Ti-C melts in dependence on cooling parameters and composition

摘要

Solidification behaviour and phase selection phenomena of undercooled stoichiometric (Nd_2Fe_14B)_100-2x+Ti_xC_X melts (x=0 to 3at percent) were investigated by the electromagnetic levitation technique and the melt spinning procedure. In-situ-temperature-time-characteristics and growth velocities of the solidification front were determiend usign pyromete,r photodiode and video data. the levitation technique allows cooling rate variations between 10 to 100 K/s, extremely low compared to melt spinning experiments (10~6 K/s). X-ray diffraction pattern of powdered samples were obtained and the phases and lattice parameters were defined.