Al-80%
TiC and Al-50%TiC grain
refiners were directly synthesized by self-propagating high-temperature synthesis (SHS) technology. The phase components and microstructures of the synthesized grain refiners were examined by XRD and SEM, and their grain
refining performances for
commercially pure aluminum were also evaluated and compared with commonly used Al-5Ti-1B grain refiner. The results show that the SHS grain refiners consist of TiC and α-(Al), and that the size and distribution of TiC
particles have significant influence on the grain refining properties of the SHS grain refiners. Al-80%TiC has poor grain refining effect because of coarser size (2～5 μm) and agglomeration of the synthesized TiC particles, whereas Al-50%TiC exhibits higher grain refining performance than Al-5Ti-1B . The addition of SHS Al-50%TiC grain refiner to the molten
Aluminum in the amount of 0.1% might transform the structure of the solidified samples from coarse columnar grains to fine equiaxed grains (average grain size 120 μm), and this grain refining effect could be maintained for 90 min at 1 003 K. SEM and TEM examinations show that submicron (0.4～0.9 μm) TiC particles in SHS Al-50%TiC grain
Refiner exhibit high thermodynamic stability in liquid aluminum, thereby affording the grain refiner excellent grain refining performance and high resistance to grain refining fading.