Preparation and Property of Gradient Ni–W–ZrO2 Composite Coating on LY12 Alloy

• Published in: Transactions of the Indian Institute of Metals 2019-05, Vol.72 (5), p.1187-1199
• Main Authors: Liu, Xiao-jia, Sun, Wan-chang, Dong, Ya-ru, Ma, Min, Zhang, Ya-gang, Yang, Fei, Ruan, Yu-yao
• Format: Article
• Language: English
• Subjects: Aluminum base alloys; Chemistry and Materials Science; Corrosion and Coatings; Corrosion prevention; Corrosion resistance; Corrosive wear; Crystal structure; Heat treatment; Materials Science; Metallic Materials; Nickel; Oxidation; Oxidation resistance; Protective coatings; Sodium tungstate; Substrates; Technical Paper; Tribology; Tungsten; Wear resistance; Zirconium dioxide
• ISSN: 0972-2815; 0975-1645
• DOI: 10.1007/s12666-019-01606-2

Combining a technology of a composite coating and a new development idea of a functionally gradient deposits, a kind of novel gradient nickel–tungsten–zirconium dioxide (Ni–W–ZrO 2 ) composite coating was successfully prepared on LY12 alloy substrate by using concentration of sodium tungstate varying as 20 g/L, 50 g/L, 80 g/L, 120 g/L, 160 g/L, and 200 g/L in the bath. The results showed that the W content of as-deposited gradient Ni–W–ZrO 2 composite coating was gradually increased to 50.50 wt% along the coating growth direction, its structure transitioned from amorphous to crystal line, and the tungsten nickel (Ni 4 W) phase was precipitated after heat treatment at 400 °C for 1 h. In addition, the wear and oxidation resistance, and anti-corrosion of gradient Ni–W–ZrO 2 composite coating were generally enhanced with increase in heat treatment temperature. Moreover, the wear resistance, oxidation and corrosion resistance of gradient Ni–W–ZrO 2 composite coating achieved optimal values after heat treatment at 400 °C for 1 h for the gradient structure and high W content.