Effects of cold rolling and heat treatment on hardness, electrical conductivity and microstructure of AMg6 aluminum alloy

Abstract

In this paper the effects of cold rolling and heat treatment on the hardness, electrical conductivity and the microstructure of AMg6 wrought aluminum alloy was studied. The experimental data shows that, AMg6 aluminum alloy is a highly malleable wrought aluminum alloy, which can be cold rolled up to 75% without being cracked or broken. As the rolling reduction increases from 0 to 75%, hardness increases respectively from 76.3 HV3 to 185.3 HV3, and electrical conductivity decreases slightly from 29.2%IACS to 25.8%IACS. The microstructure of the alloy changes strongly, the particles are stretched along the rolling direction, especially the samples with the level of cold rolling up to 75%. After recrystallization annealing, the hardness decreased slightly after annealing at about (100-200) oC and decreased quickly after annealing at about (300-400) oC for 4 hours. Сonversely, the electrical conductivity increases rapidly when annealed for the first hour, then increases slightly. After 4 hours of annealing at (100-200) oC for, the electrical conductivity increases almost not significantly, meanwhile at (300-400) oC, the electrical conductivity increases significantly, the value is almost equal to value of the original specimen. The deformed particles are gradually replaced by new ones, which are more obvious when annealing at high temperature, about (300-400) oC. These research results are the basis for selecting technological parameters in fabricating AMg6 alloy and are the premise for further studies to improve the properties of this alloy, serving to manufacture dualpurpose parts, especially weapon parts.