Grain refining performance of SHS Al-50TiC master alloys for commercially pure aluminum

Abstract

An Al-50wt% TiC composite was directly synthesized by self-propagating high-temperature synthesis (SHS) technology, and then was used as a grain refining master alloy for commercially pure aluminum. the microstructure and grain refining performance of the synthesized master alloy were emphatically investigated. The SHS master alloy only contained submicron TiC particles except for Al matrix. Moreover, TiC particles were relatively free of agglomeration. Grain refining tests show that adding only 0.1 wt% of the master alloys to the aluminum melt could transform the structure of the solidified samples from coarse columnar grains to fine equiaxed grains (average grain size 120 μm), and that this grain refining effectiveness could be maintained for almost 1. 5h at 1003 K. Therefore, it is concluded that the SHS master alloy is an effective grain refiner for aluminum and its alloys, and that it is highly resistant to the grain refining fading encountered with most grain refiners.