CRYSTAL GRAIN REFINING AGENT FOR CASTING AND METHOD FOR PRODUCING THE SAME

摘要

[Object] To provide a grain refiner for casting; and a method for producing the same. The grain refiner contains heterogeneous nucleator particles having a smaller degree of mismatching ´ with respect to pure aluminum or an aluminum alloy than those of customary grain refiners. [Solution] The grain refiner is produced by rapid and low-temperature sintering through spark plasma sintering. The grain refiner contains heterogeneous nucleator particles that have a small degree of mismatching and originally fail to exist in equilibrium with aluminum. Typically spark plasma sintering gives a grain refiner for casting which includes an aluminum matrix; and particles of an L1 2 structure Al 5 CuTi 2 intermetallic compound dispersed in the matrix. The grain refiner, when added to a molten metal, gives a pure-aluminum or aluminum-alloy cast material having a refined and uniformized microstructure.