The invention provides a rare-earth
alloy. Elements Mg and Si co-fine a strengthening phase Mg2Si in an
ageing thermal treatment process, so that
dislocation motion is effectively inhibited and the effect of strengthening a base body is achieved; Al-Ti-B and rare-earth elements are added to form a heterogeneous
nucleation core with relatively low mismatching degree with an alpha-Al substrate lattice for performing grain reinforcement on the aluminum
alloy, and impurities in the aluminum
alloy are purified; elements Cr and Mn are added to inhibit growth advantages in single direction of a needle-like Fe phase, so that the needle-like Fe phase changed into a Chinese character shaped or granular Fe-containing phase; elements Sr and Ca are introduced to introduce eutectic
silicon to form high-density twin
crystal, so that optimization of the morphology of eutectic
silicon is realized. Elements mutually act, so that a base phase alpha-Al, eutectic
silicon and a Fe phase of the alloy have excellent
microscopic morphology, and thus, the purposes of strengthening the alloy, refining the
crystal grains and optimizing the structure morphology are achieved, and a rate of elongation of the alloy is remarkably increased.