The preparation process and properties of coating of machesium alloy by arc spraying with aluminum
Qiao Qi
CNKI
Abstract
The magnesium alloy has specific strength and stiffness, damping, it can defend electromagnetism and anti-radiation strongly, it can be easily cutted and reclaimed, and a series of advantages, it has an extremely important value and broad application prospects in the automotive, electronics, appliances, transportation, aerospace, aviation and defense industries. It is the third class of metallic structural materials following steel and aluminum alloy developed, it is called the 21st century green engineering material.
However, because the standard electrode potential of pure magnesium is low, at-2.37 V, so the corrosion of magnesium alloy comes to be the main problems for a long time greatly limits its wide application in engineering.
In this paper, I make a layer of anti-corrosion coating on the surface of magnesium alloy through arc spraying with aluminum. First, determining the optimum combination of parameters of the arc spraying of aluminum by orthogonal test, the spraying voltage should be at 27.9 V, the spraying distance should be at 150 mm, and the air pressure should be from 0.6 to 0.8 Mpa; Then reaserch the organizational structure and morphology of the coating , the corrosion resistance of the coating, the bond strength between the coating and the substrate, hardness of the coating and heat treatment on the arc spraying quality. After arc spraying with aluminum, the pitting time of the sample extends to 288 hours from 4 hours. After heating for 2 hours at 400 ℃, the corrosion resistance of the coating and the bonding strength have been improved significantly.
Keywords: magnesium alloy; arc spraying; corrosion resistance; bond strength; heat treatment
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