Effects of Severe Plastic Deformation and Ultrasonic Treatment on the Structure, Strength, and Corrosion Resistance of Mg-Al-Zn Alloy

Nowadays, there is a great demand for increasing the strength and corrosion resistance of magnesium alloys for their wider use in machine engineering, oil industry, and medicine. This paper is devoted to a study on the effects of the combined process of reduction and equal channel angular pressing, as well as the subsequent ultrasonic irradiation on the structure, strength, and corrosion properties of the Mg-Al-Zn alloy. Deformation processing results in an increase of the strength up to 280 +/- 10 MPa. A fine-grained structure is formed with a grain size of 10-20 mu m and small recrystallized grains 1-2 mu m in size. The corrosion resistance in the HCl medium falls down significantly. Action of ultrasound on the deformed specimen leads to an increased fraction of high-angle boundaries, in particular, the fractions of special, fully overlapping sigma 13a boundaries and twin boundaries of sigma 15b and sigma 17a systems. Due to the ultrasonic treatment, the strength of the Mg-Al-Zn alloy increases up to 310 +/- 5 MPa, while the corrosion resistance in HCl almost doubles.

Automated summary

This study investigates the effects of the combined process of reduction and equal channel angular pressing, as well as subsequent ultrasonic irradiation, on the structure, strength, and corrosion properties of Mg-Al-Zn alloy. The deformation processing resulted in increased strength but reduced corrosion resistance in HCl medium. Ultrasonic treatment led to further improvement in strength and corrosion resistance of the alloy.