Electric current assisted sintering of continuous functionally graded Ti2AlN/TiN material

A Ti/AlN powder mixture with a molar ratio of 2:1 was consolidated by electric current assisted sintering (ECAS) using a special designed graphite die which can give rise to a huge temperature gradient along the vertical direction in the sintering compact. By this way, a continuous microstructural evolution during the formation of Ti2AlN was observed. At 1200 degrees C, a Ti2AlN TiN composite was prepared through the in situ decomposition of Ti2AlN. The SEM and XRD results revealed that a continuous variation of Ti2AlN and TiN phase content was achieved. The gradual hardness distribution across the entire composite further indicated that a continuous functionally graded Ti2AlN/TiN material was obtained rapidly by taking advantage of the ECAS method. (C) 2011 Elsevier Ltd and Techna Group S.r.l. All rights reserved.