High-concentration　Al–Ti–B　master　alloy　was　prepared　by　melt　self-propagating　high-temperature　synthesis,　and　then　the　extruder　bar　of　intermediate　alloy　was　also　prepared.　The　grain　refiner　can　be　divided　into　two　categories.　One　is　TiB2　particles　only,　and　the　other　is　two　particulate　matter　containing　both　TiB2　and　TiAl3.　The　microstructures　of　the　two-grain　refiners　were　observed　under　scanning　electron　microscope　(SEM)　and　compared　with　the　commercial　refiners.　The　fining　effects　of　the　two-grain　refiners　were　analyzed.　The　refining　mechanism　of　TiAl3　and　TiB2　was　discussed,　and　the　optimum　dosage　and　the　refinement　scheme　of　pure　aluminum　were　optimized.　©　2019,　Springer　Nature　Singapore　Pte　Ltd.