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铸态铍铝合金组织为粗大的柱状树枝晶,提高冷却速度或塑性变形能细化晶粒,减小柱状晶区面积,提高力学性能。结果表明,当冷却速度达300℃/s时,Be-38Al合金晶粒尺寸仅为5~10μm,铸锭表现为完全的等轴晶组织。铸造Be-38Al合金经热压变形后,柱状晶发生碎化。在500℃将热压坯锭由16.5 mm轧制至5.0 mm,枝晶组织进一步碎化,一些区域形成沿轧制方向变形拉长的晶粒,这表明Be-38Al合金在轧制过程中未发生动态再结晶。与铸态合金相比,Be-38Al合金的热轧板材力学性能提高,抗拉强度由61.5 MPa提高到269.8 MPa,伸长率由2.0%提高到3.5%。
As-cast beryllium aluminum alloy coarse columnar dendrite, to improve the cooling rate or plastic deformation can refine the grain, reduce the area of columnar crystal area, improve the mechanical properties. The results show that when the cooling rate reaches 300 ℃ / s, the grain size of Be-38Al alloy is only 5 ~ 10μm, and the ingot shows complete equiaxed grain structure. Cast Be-38Al alloy after hot deformation, the columnar crystal fragmentation. The hot-rolled billets were rolled from 16.5 mm to 5.0 mm at 500 ° C, the dendritic structure further shredded, and some regions formed grains that elongated in the rolling direction, indicating that the Be-38Al alloy was not rolled during rolling Occurred dynamic recrystallization. Compared with the as-cast alloy, the mechanical properties of the Be-38Al alloy hot rolled sheet increased, the tensile strength increased from 61.5 MPa to 269.8 MPa, and the elongation increased from 2.0% to 3.5%.