Effects of Nd Addition on the Microstructure and Mechanical Properties of Extruded Mg-6Gd-2.5Y-0.5Zr Alloy

• Published in: Journal of materials engineering and performance 2018-01, Vol.27 (1), p.243-252
• Main Authors: Guan, Liqun, Deng, Yunlai, Shi, Hongji, Yang, Liu, Chen, Mingan
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Corrosion and Coatings; Engineering Design; Materials Science; Quality Control; Reliability; Safety and Risk; Tribology
• ISSN: 1059-9495; 1544-1024
• DOI: 10.1007/s11665-017-3089-5

The microstructure, age-hardening behavior, mechanical properties and texture of extruded Mg-6Gd-2.5Y-0.5Zr alloys with various additions of Nd have been investigated through optical microscopy, x-ray diffraction, scanning electron microscopy, transmission electron microscopy, electron back-scattered diffraction, hardness and tensile tests. The results indicate that the number of second-phase particles in the as-extruded alloys increases (especially with the addition of 1.5 wt.% Nd), and the amount of the strengthening β ′ phase in the peak-aged sample initially increases, and then decreases when the content of Nd increases above 1.0 wt.%. The precipitation of second-phase particles in the extrusion process weakens the age strengthening. The peak-aged Mg-6Gd-2.5Y-1Nd-0.5Zr alloy shows a maximum yield strength of 259 MPa and an ultimate tensile strength of 350 MPa, which can be attributed to the finely dispersed strengthening β ′ phase. All as-extruded alloys exhibit that (0001) planes are aligned perpendicular to the extrusion direction, and the maximum intensity of the texture increases gradually with Nd addition.