摘要
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 Be-Al alloy exhibits coarse columnar dendritic structure. Increasing cooling rate or plastic deformation could refine the grain and decrease the area of columnar zone then the mechanical properties improve. The results show that when the cooling rate is 300℃/s, the grain size of Bc-38Al alloy is approximately 5-10 μm, and the ingot presents complete equiaxed structure. After hot pressing, the columnar dendrite of Be-38Al alloy generates fragmentation. Bo-38Al alloy plates with 16.5 mm in thickness are hot-rolled to 5.0 mm at 500℃, then, the dendritic structure is furtherly liagmcntcd. Some grains deform and stretch along the rolling direction, which indicates that the dynamic rccrystallization does not take place during rolling. Compared with as-cast alloy, the mechanical properties of hot-rolled Be-38Al alloy significantly improve, then, the tensile strength and elongation increase from 61.5 MPa and 2.0% to 269.8 MPa and 3.5%, respectively.
出处
《热加工工艺》
CSCD
北大核心
2016年第22期105-108,共4页
Hot Working Technology
基金
国家自然科学基金项目(51504226)
关键词
铍铝合金
冷却速度
热轧
显微组织
Bc-Al alloy
cooling rate
hot-rolling
microstructure
