Effect of Al₂ Gd on microstructure and properties of laser clad Mg-Al-Gd coatings

Journal
Applied surface science  
Volume
330
Start Page
393
End Page
404
Citation
Applied Surface Science (330): 393-404 (2015-03-01)
Publisher DOI
10.1016/j.apsusc.2014.11.132
Scopus ID
2-s2.0-84924032979
In order to investigate the effects of Gd addition on the microstructures and properties of magnesium coatings, the Mg-7.5Al-xGd (x = 0, 2.5, 5.0 and 7.5 wt.%) coatings on cast magnesium alloy were fabricated by laser cladding with wire feeding. The results indicated that the gadolinium (Gd) addition led to the formation of a cubic Al 2 Gd phase as well as suppressed the precipitation of eutectic Mg 17 Al 12 phase. The laser clad coating containing nominally 7.5 wt.% Gd presented the highest microhardness, ultimate tensile strength and yield strength at both room temperature and high temperatures. The enhancement of heat resistant capacities was chiefly attributed to the existence of thermally stable Al 2 Gd particles, which prevented tiny liquation of eutectic phases along the grain boundaries and made great contributions on maintaining high yield ratio during high-temperature deformation.
Subjects
Gadolinium
Laser cladding
Magnesium alloy
Microstructure
Property