Enhancing hot corrosion performance of NiCoCrAlY/AlSiY coating by arc enhanced glow discharge

Abstract

A promising arc enhanced glow discharge (AEGD) was developed to enhance hot corrosion resistance of NiCoCrAlY/AlSiY coating. The AlSiY layer exhibited loose texture accompanied by plenty of pores, which triggered the muti-scale diffusion of salt mixture resulting in severe corrosion degradation of coating texture and rapid diffusion of NiCoCrAlY layer. However, the AEGD-assisted AlSiY layer showed dense texture, which effectively prevented the diffusion of salt mixture and suppressed the corrosion reaction as well as the diffusion of NiCoCrAlY layer. The results confirmed that AEGD showed a huge potential to inhibit the corrosion damage and diffusion of thermal protective coatings.

Keywords

• Ti6Al4V alloys
• Thermal protective coatings
• Arc enhanced glow discharge
• Hot salt corrosion
• Diffusion