Fabrication of titanium diboride-carbon core-shell structure particles and their application as high-efficiency grain refiners of wrought aluminum alloys

A facile method for the synthesis of titanium diboride core-shell structure particles (TiB2@C) was developed utilizing the transformation from TiC to TiB2 in aluminum melt. The particles display hexagonal platelet morphology, with a length of about 800 nm and a thickness of about 200 nm. Carbon layers 4 nm thick are homogeneously coated on the TiB2. Grain refining tests on commercial pure aluminum alloy indicate that TiB2@C particles display a higher grain refining efficiency than TiB2.