The dynamic evolution of microstructure and mechanical properties of an Al–Cu–Li alloy during multi-axial compression

Abstract

A 2297 aluminum-lithium alloy was subjected to multi-axial compression (MAC) at 160 °C to obtain different cumulative strains. The room temperature tensile test, transmission electron microscopy and X-ray diffraction techniques were used to study the microstructural evolution and mechanical properties of Al–Cu–Li alloy. It was observed that the ultimate tensile strength was increased from 267 MPa to 480 MPa and the hardness was increased from 55 HV to 141 HV by high-density dislocations and precipitation phases. Due to the massive amount of precipitation occurring at dislocations and the subsequent high strain introduced to destroyed it, the size of the precipitates was effectively reduced, the fine precipitates delayed the strain localization, the alloy obtained high elongation (~11.2 %).

Keywords

• MAC
• Al–Cu–Li alloy
• Dynamic precipitation
• Mechanical properties