摘要
采用热压缩试验、光学显微镜和透射电子显微镜(高分辨电镜)研究了再结晶分数对Al-Zn-Mg-Cu合金淬火敏感性的影响。结果表明:7050合金的淬火敏感性、平衡相尺寸及面积分数随再结晶分数的增加递增,再结晶的面积分数与η相的面积分数具有很好的线性相关性。再结晶分数从10%增加至58%时,相对硬度值从7%增加至17%,平衡相的长度和厚度分别由265 nm和35 nm增加至422 nm和82 nm,其平衡相的面积分数也从6.5%增加至28.4%。亚晶晶内的Al_3Zr粒子,与基体的共格性很好,慢速淬火过程中,不利于平衡性的析出;而在再结晶晶内的Al_3Zr粒子有利于η相的析出,再结晶分数越多,与基体非共格的Al_3Zr粒子越多,η相的形核位置越多,从而导致淬火敏感性增加。
The effect of recrystallization fraction on quench sensitivity of Al-Zn-Mg-Cu alloys was investigated by means of thermal compression test, optical microscopy, and high-resolution transmission electron microscopy. Results show that the quench sensitivity, the size and area fraction of equilibrium phase for 7050 alloy increases with the increase of recrystallization fraction. The area fraction of recrystallization has a good linear correlation with the area fraction of equilibrium phase. When the recrystallization fraction increases from 10% to 58%, the relative hardness value increases from 7% to 17%, the length and thickness of the equilibrium phase increase from 265 nm and 35 nm to 422 nm and 82 nm, respectively, while the area fraction of the equilibrium phase also increases from 6.5% to 28.4%. The Al3Zr particles in the sub-grained crystals have good coherency with the matrix, which are unfavorable to the equilibrium precipitation during the slow quenching process. However, the Al3Zr particles in the recrystallized grains are beneficial to the equilibrium precipitation. The more recrystallization fractions, the more particles that are incoherent with the matrix,so the more nucleation sites are precipitated by quenching,resulting in the increment of quench sensitivity.
作者
李承波
邓运来
唐建国
李建湘
张新明
Chengbo LI;Yunlai DENG;Jianguo TANG;Jianxiang LI;Xinming ZHANG(School of Materials Science and Engineering, Central South University, Changsha 410083, China;Guangdong Hoshion Industrial Aluminium Co. Ltd., Zhongshan 528463, China)
出处
《材料研究学报》
EI
CAS
CSCD
北大核心
2018年第12期881-888,共8页
Chinese Journal of Materials Research
基金
国家重点研发计划(2016YFB0300900)
国家自然科学基金(51474240)
中山市科技局重大专项(2016A1001)~~
