  Magnesium (Mg) and its alloys have a great potential as structural materials
due to their beneficial combination of high strength to weight ratio, high
thermal conductivity and good machinability. However, few literatures about Mg
coatings fabricated by cold spraying can be found. In this study, Mg coatings
were fabricated by cold spraying, and the microstructure, phase structure,
oxygen content and microhardness of the coating prepared under different main
gas temperatures were investigated. The critical velocity of the particle was
evaluated through numerical simulations. The particle deformation behavior and
bonding mechanism were discussed. The result of the oxygen content test shows
that the oxygen contents of the coatings did not increase comparing with that
of the feedstock powder. The simulation results show that the critical velocity
of Mg particles was in a range of 653 m/s to 677 m/s. The observation of the
coating fracture morphology shows that the formation of the coating was due to
the intensive plastic deformation and mechanical interlocking. The
microhardness of the coating increased with the increase of the main gas
temperature from 350oC to 450oC due to the decrease of the coating porosity.
