Dissolution behavior of nano-sized precipitates in aged Al-Si-Mg-Cu alloy during cold deformation

Dissolution of precipitates is an important phenomenon during the cold deformation of aged Al-Si-Mg-Cu alloys, which significantly affects the alloy's mechanical and conductive behavior. Here, we reveal its mechanism via nanometer scale observation on the microstructural evolution of a representative Al-Si-Mg-Cu aluminum alloy. The accumulation of dislocations led to micro tensile stress from both ends to the middle of the precipitates, and caused the precipitates sequentially to transform into smaller particles, Guinier-Preston zones and solute atoms. The increasing number density of fractured precipitates and the cumulative lattice adsorption energy are the major driven force of the dissolution process. These findings are crucial for laying down the thermomechanical treating technology of such alloys to improve their mechanical and conductive performance.

Automated summary

The dissolution of precipitates during cold deformation in aged Al-Si-Mg-Cu alloys plays a crucial role in the mechanical and conductive behavior of the alloys. Through nanometer scale observation, this study reveals that the accumulation of dislocations leads to the transformation of precipitates into smaller particles, Guinier-Preston zones, and solute atoms. The increasing number density of fractured precipitates and the cumulative lattice adsorption energy are the main driving forces behind the dissolution process. These findings are essential for improving the thermomechanical treatment technology of such alloys to enhance their mechanical and conductive performance.