Effects of aging treatment on the precipitation behaviors and mechanical properties of Al-5.0Mg-3.0Zn-1.0Cu cast alloys

This study investigates the relationship between aging temperature on the precipitation behavior and mechanical properties of a gravity cast Al-5.0Mg-3.0Zn-1.0Cu (wt%) alloy. After solution treatment at 470 °C for 24 h, alloys were aged at 120, 150 and 175 °C. Upon analyzing the samples, the alloys...

Full description

Saved in:
Bibliographic Details
Published in:Journal of alloys and compounds 2020-11, Vol.842, p.155707, Article 155707
Main Authors: Tang, Hua-Ping, Wang, Qu-Dong, Luo, Colin, Lei, Chuan, Liu, Tian-Wen, Li, Zhong-Yang, Jiang, Hai-Yan, Ding, Wen-Jiang, Fang, Jian, Zhang, Jian-Wei
Format: Article
Language:English
Subjects:
Age hardening
Aging
Aging (artificial)
Aging treatment
Al-Mg-Zn-Cu cast alloys
Alloys
Automotive parts
Casting alloys
Elongation
Heat treating
Impact strength
Impact toughness
Mechanical properties
Precipitates
Precipitation hardening
Solution heat treatment
Tensile tests
Toughness
T′ precipitates
Ultimate tensile strength
Yield strength
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:This study investigates the relationship between aging temperature on the precipitation behavior and mechanical properties of a gravity cast Al-5.0Mg-3.0Zn-1.0Cu (wt%) alloy. After solution treatment at 470 °C for 24 h, alloys were aged at 120, 150 and 175 °C. Upon analyzing the samples, the alloys displayed different age hardening behaviors due to the variations in aging temperature. An increase in aging temperature not only reduced the peak aging time significantly, but also changed the distribution of precipitates. Numerous GPII zones and T′ precipitates (precursors of T-Mg32(AlZn)49) were homogeneously distributed within matrix at a higher aging temperature and the volume fraction of T′ precipitates increased. Tensile test results for peak-aged samples determined that both yield strength (YS) and ultimate tensile strength (UTS) increased, while elongation (EL) decreased with increasing temperature. The increase in the YS can be attributed to the higher volume fraction of T′ precipitates caused by the higher aging temperature. Moreover, the impact toughness decreased (due to a continuous decrease in EL) as the aging temperature increased. By adjusting aging temperature from 120 to 175 °C, YS increased from 377 to 451 MPa, while EL decreased from 13.8% to 5.2%. After peak aging treatment at 150 °C, the alloy appears to possess optimal mechanical properties with YS, UTS, EL and toughness being 441 MPa, 496 MPa, 9.6%, and 8.1 J/cm2, respectively. These finding suggest that there are many potential advantageous applications for this alloy within automobile components requiring high strength and toughness. [Display omitted] •A high strength cast Al alloy related to T′ precipitates is developed.•A higher aging temperature increases strength, but reduces EL and impact toughness.•By adjusting aging temperature can control the size distribution of precipitates.•A higher aging temperature increases the volume fraction of T′ precipitates.
ISSN:0925-8388
1873-4669
DOI:10.1016/j.jallcom.2020.155707