Doubling of the strength and plasticity of a commercial aluminum-based alloy (AMg6) processed by equal channel angular pressing

A study was conducted to increase the ultimate tensile strength of the AMg6 aluminum alloy at room temperature to 400-450 MPa and increase its plasticity 1.5-2 times. AMg6 was used from industrial melt no. 13-3157, while equal channel angular pressing (ECAP) was carried out in a device with an intersection angle of 90° between the working and output channels. It is found that the thermal treatment at a temperature of 300°C and higher improves 2-2.5 times the plastic characteristics of the microcrystalline AMg6 alloy and reduces the material strength by 25%. The high plasticity of the microcrystalline AMg6 alloy at temperatures within 200-275°C is explained using the development of low-temperature superplasticity. The activation energy in the mirocrystalline AMg6 alloy amounts to 65 KJ/mole, which is 20% lower than the usual values of activation energy of the grain-boundary diffusion controlling the process of superplastic flow.