Preparation and corrosion resistance of MAO/Ni–P composite coat on Mg alloy

Corrosion behavior of a self-sealing pore micro-arc oxidation film on AM60 magnesium alloy

“…Typical MAO films have a ceramic structure with relatively high porosity [5][6][7]. In the corrosion process, the structural imperfection in the MAO films enlarges the effective surface areas for corrosion, while the large micro-pores act as the passages for corrosive ions entering into the MAO films [8][9][10]. Consequently, the corrosion resistance of the MAO films decreases.…”

A novel palladium-free surface activation process for electroless nickel deposition on micro-arc oxidation film of AZ91D Mg alloy

“…According to the reports by Liyun Zeng et al [14] and Xizhi Fan et al [15], a combination of anodic oxidation and EN plating might be able to provide better corrosion resistance for Mg alloy. MAO/ Ni-P composite coatings exhibit dense top coating and stable bonding interface.…”

Microstructural characterisation of air plasma sprayed nanostructure ceramic coatings on Mg–1%Ca alloys (bonded by NiCoCrAlYTa alloy)

“…Regrettably, microstructure of the PEO coatings is porous (including micro-pores, microcracks and micro-channels). This can reduce the surface quality of the PEO coatings and can facilitate the infiltration of corrosive solution into the Mg substrate [16][17][18]. Moreover, aforementioned coatings could not provide desirable mechanical properties such as high hardness and excellent wear resistance compared to untreated Mg alloys.…”

“…Recently, plasma electrolytic oxidation (PEO) method has been used to produce coatings with special properties such as inert ceramic-like composition, excellent bond strength with substrate, relatively high thickness and hardness on the Mg alloys. Thus, PEO coatings on the Mg alloys have been studied by many investigators [15][16][17][18]. Regrettably, microstructure of the PEO coatings is porous (including micro-pores, microcracks and micro-channels).…”