Influence of nitrogen on the synthesis and nucleation ability of TiCx in Al-Ti-C master alloy

In this study, a group of Al-Ti-C master alloy has been prepared in an atmosphere with different concentration of N-2. The master alloys are analyzed by field emission scanning electron microscope (FE-SEM) and transmission electron microscope (TEM). It is discovered that N atoms can be doped into TiCx at a certain concentration of N2 while it will form AlN if the concentration is higher. Adding Al-Ti-C master alloy with N doped TiCx particles in molten aluminum, the average grain size of alpha-Al can be reduced from 3320 mu m to 189 mu m and the efficiency does not fade within 60 min. It is supposed that the grain refinement efficiency and stability of TiCx is improved obviously after N doping. This master alloy exhibits potential to promote the application of grain refiner in industries. (C) 2014 Elsevier B.V. All rights reserved.