【摘要】 通过力学性能测试与微观组织表征相结合的实验方法,研究Sc元素的添加对X2A66合金的微观组织演变以及力学性能影响规律。结果表明:在X2A66合金中添加质量分数为0.18%的Sc元素,可有效细化铸态合金晶粒尺寸;并形成尺寸较大的AlScZr或AlCuScZr初生相;提高铸态合金的过烧温度;与Al₃Zr粒子相比,Al₃（Sc,Zr）复合粒子的抑制再结晶的作用效果更佳,在后续的变形和热处理过程中使合金具有更小的晶粒尺寸,但AlCuSc和AlCuScFe相在后续热处理过程中不能完全溶解,从而损害了固溶态合金的力学性能。更多还原

【Abstract】 The effects of Sc addition on the microstructure evolution and mechanical properties of X2A66 alloy were studied by the experimental methods of mechanical property test and microstructure characterization. The results indicate that adding 0.18% Sc element in the X2A66 alloy can effectively refine the grain size, and form the primary phase of AlScZr or AlCuScZr with larger size,and also increases the over firing temperature of the as-cast alloy. Compared with Al₃Zr particles, Al₃（Sc, Zr） composite particles have better effect on restraining recrystallization, and make the alloy have smaller grain size during the subsequent deformation and heat treatment. However, AlCuSc and AlCuScFe phases can not be completely dissolved in the subsequent heat treatment process,which damages the mechanical properties of the solid solution alloy.更多还原