Effects of single-side and double-side friction stir processing on microstructure and properties of Mg-Zn-Y-Nd alloy thick plate

Abstract

In order to obtain a large modified zone with uniform microstructure and good comprehensive properties, single-side and double-side friction stir processings of Mg-Zn-Y-Nd alloy thick plate were carried out, and the microstructure and properties of the processed plates were studied. The results show that the microstructure of the alloy is obviously refined after friction stir processing. The average grain sizes of the upper, mid and lower samples in the stirring zone after single-side and double-side friction stir processings are 4.45 μm, 5.08 μm,5.30 μm and 3.93 μm, 3.20 μm and 3.19 μm respectively. Compared with the homogenizing annealing alloy and single-side friction stir processed alloy, the microstructure of the double-side friction stir processed alloy is more uniform and fine, and the tensile strength and elongation of the lower stirring zone are the highest, 283.3 MPa and 23.9% respectively, and also the corrosion resistance is the best. The corrosion mode is changed from pitting corrosion to uniform corrosion.

Keywords

• Mg-Zn-Y-Nd alloy
• thick plate
• friction stir processing
• microstructure
• mechanical properties
• corrosion resistance