Effect of Annealing Temperature on the Water Contact Angle of PVD Hard Coatings

Materials

Yu-Sen Yang¹ 

[1] Department of Mechanical and Automation Engineering, National Kaohsiung First University of Science and Technology, 2 Juoyue Rd., Nantz District, Kaohsiung 81164, Taiwan

关键词: nitride;    DLC;    hydrophobic;    hydrophilic;    water contact angle;    anti-sticking;   

DOI  :  10.3390/ma6083373

来源: mdpi

【 摘 要 】

Various PVD (physical vapor deposition) hard coatings including nitrides and metal-doped diamond-like carbons (Me-DLC) were applied in plastic injection and die-casting molds to improve wear resistance and reduce sticking. In this study, nitrides hcp-AlN (hexagonal close-packed AlN), Cr₂N, (CrAl)₂N) and Me-DLC (Si-DLC and Cr-DLC) coatings were prepared using a closed field unbalanced magnetron reactive sputtering system. The coatings were annealed in air for 2 h at various temperatures, after which the anti-sticking properties were assessed using water contact angle (WCA) measurements. The as-deposited hcp-AlN, Cr₂N and (CrAl)₂N coatings exhibit hydrophobic behavior and exhibit respective WCAs of 119°, 106° and 101°. The as-deposited Si-DLC and Cr-DLC coatings exhibit hydrophilic behavior and exhibit respective WCAs of 74° and 88°. The annealed Cr₂N and (CrAl)₂N coatings exhibit hydrophobic behavior with higher WCAs, while the annealed hcp-AlN, Si-DLC and Cr-DLC coatings are hydrophilic. The increased WCA of the annealed Cr₂N and (CrAl)₂N coatings is related to their crystal structure and increased roughness. The decreased WCA of the annealed hcp-AlN, Si-DLC and Cr-DLC coatings is related to their crystal structures and has little correlation with roughness.

【 授权许可】

CC BY   
© 2013 by the authors; licensee MDPI, Basel, Switzerland.