New insights into the growth mechanism of 3D-printed Al2O3–Y3Al5O12 binary eutectic composites.

We investigated the complex solidification behaviour of Al 2 O 3 –Y 3 Al 5 O 12 eutectics prepared by laser engineered net shaping. Colony structure consisting of coupled irregular eutectic was dominant at interior region of as-fabricated specimens, and its growth behaviour was depicted by Magnin–Kurz model. In each deposited layer, The Y 3 Al 5 O 12 phase within irregular eutectic grew through a competitive mechanism from random to oriented, whereas the orientation of Al 2 O 3 remained unchanged. Transition from anomalous to colony coupled eutectics occurred at the bottom of each layer, and irregular to regular eutectics transition was recognized at outer region of as-built sample. Image, graphical abstract [ABSTRACT FROM AUTHOR]