Open AccessEnhancement of strength mechanical and corrosion resistance of 7055 alloy with minor Sc and Y addition
Author(s) -
Kai Huang,
Qin Feng,
Wenbiao Zhou,
Ren Yuelu,
Liang Huang,
Jing Xiang,
Hongqun Tang,
Yutao Zhu,
Yuezhou Wei
Publication year - 2021
Publication title -
materials research express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.383
H-Index - 35
ISSN - 2053-1591
DOI - 10.1088/2053-1591/abda06
Subject(s) - materials science , alloy , ultimate tensile strength , eutectic system , metallurgy , corrosion , precipitation , vickers hardness test , precipitation hardening , grain size , microstructure , conductivity , chemistry , physics , meteorology
A new type of 7055-Y-Sc alloy with high strength and corrosion resistance was prepared. Eutectic Al 3 Y particles with sizes in the range of 500–600 nm were found in the as-cast structure of the 7055-Y-Sc alloys. The addition of Y significantly accelerated the precipitation of Al 3 Zr with L1 2 structure in Al–Zr–Y alloy, and the number density of Al 3 (Zr, Y) precipitates was almost a grade higher than that of Al 3 Zr. In the process of aging at 120 ℃/12 h, the nano scale L1 2 -type Al 3 (Sc x Y y ) phase nucleated uniformly within the Al matrix and nonuniformly on the dislocation. The grain size decreased from 100–200 um in 7055-Y-0Sc to 40–50 um in 7055-Y-0.25Sc, the percentage of Sc continued to increase, and the grain size remained unchanged or even increased, thereby decreasing the Vickers hardness of 7055-Y-Sc alloys from 196.4 HV to 187.9 HV. After aging, the hardness and tensile properties of 7055-Y-Sc alloy showed good performance. The effective Sc proportion of the 7055-Y-Sc alloy was 0.25%. Its tensile strength was 398.6 MPa. Its conductivity was 33.8% IACS. The current corrosion density was 6.7 × 10 −8 A cm −2 , its good strength, corrosion resistance and conductivity make the studied alloy to be a promising material.