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

• A group of Al–Ti–C master alloy has been prepared in different concentration of N2.
• It is found that N atoms can dope into TiCx at a certain concentration of N2.
• The effect of N element on the nucleation ability of TiCx on α-Al is investigated.
• The excellent refining performance of the doped TiCx does not fade within 60 min.

In this study, a group of Al–Ti–C master alloy has been prepared in an atmosphere with different concentration of N2. 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 α-Al can be reduced from 3320 μm to 189 μm 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.