Open AccessRelationship between cooling rate, microstructure evolution, and performance improvement of an Al–Cu alloy prepared using different methods
Author(s) -
Chen He,
Yu Wei,
Yong Li,
Zhaodong Wang,
Di Wu,
Guangming Xu
Publication year - 2020
Publication title -
materials research express
Language(s) - English
Resource type - Journals
ISSN - 2053-1591
DOI - 10.1088/2053-1591/abc4f9
Subject(s) - microstructure , materials science , alloy , eutectic system , ultimate tensile strength , scanning electron microscope , optical microscope , casting , grain boundary , precipitation , grain size , metallurgy , composite material , dendrite (mathematics) , transmission electron microscopy , nanotechnology , geometry , mathematics , meteorology , physics
The relationship between the cooling rate and microstructure evolution and the performance improvement of an Al–4.5 wt% Cu alloy prepared using different casting methods was investigated. The microstructure evolution, solute element distribution, and mechanical properties of specimens prepared using different cooling rates were systematically investigated using multi-scale optical microscopy, scanning electron microscopy, transmission electron microscopy, tensile testing, and hardness testing. Upon increasing the cooling rate from 1.65 to 117.3 K s −1 , the average grain size, secondary dendrite arm spacing, and width and area fraction of eutectic phases significantly decreased, and the density of the precipitated phase, super-saturation degree of solute elements, and mechanical properties improved. Through a combination of grain-boundary, solid-solution, and precipitation strengthening, the cooling rate indirectly affected the mechanical properties of the heat-treated alloy sheets. The Al−4.5 wt% Cu alloy prepared by twin-roll casting under a cooling rate of 117.3 K s −1 exhibited a strength between 145.33 and 321.79 MPa and an elongation of 11.65%, demonstrating its potential as a high-performance aluminium alloy.