中國(guó)有色金屬學(xué)報(bào)(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 28 No. 11 November 2018 |
（1. Key Laboratory for Anisotropy and Texture of Materials, Ministry of Education, School of Materials Science and Engineering, Northeastern University, Shenyang 110819, China;
2. Department of Applied Science, University of Quebec at Chicoutimi, Quebec, G7H 2B1, Canada）
Abstract:The effects of quenching in different ways following solid-solution treatment on properties and precipitation behaviors of 7050 alloy were investigated by transmission electron microscopy (TEM), scanning electron microscopy (SEM), selected area electron diffraction (SAED), hardness and electrical conductivity tests. Results show that after quenching in different ways, electrical conductivity of the alloy decreases rapidly in the first 48 h of natural aging. The electrical conductivity of 7050 alloy in natural aging state is determined by the size and density of GP zones, and the size of GP zones is the main factor. After natural aging for 70 d, the size of GP zones is 1.8-2.6 nm in matrix of the immersion quenched sample and it is 1.4-1.8 nm in matrix of both water mist and forced air quenched samples. After natural and artificial peak aging, the hardness of the water mist quenched sample is HV 193.6 and its electrical conductivity is 30.5% (IACS) which are both higher than those of the immersion quenched sample. Therefore, water mist quenching is an ideal quenching method for 7050 alloy sheets after solid-solution treatment.
Key words: 7050 aluminum alloy; quenching method; precipitation behavior; electrical conductivity; nucleation site
