Inspired square micro-texture structures designed by nanosecond laser sculpture for enhancing adhesion strength of plasma spraying Si-HfO2 bond coat on SiC substrates

• Published in: Optics and laser technology Vol. 175; p. 110840
• Main Authors: Yu, Shuang, Wang, Yaming, Wang, Shuqi, Zhao, Qiang, Li, Yang, Ren, Dawei, Chen, Guoliang, Zou, Yongchun, Ouyang, Jiahu, Jia, Dechang, Zhou, Yu
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.08.2024
• Subjects: Adhesion strength; Laser surface texture; Mechanical anchoring; Residual stress; Mechanical anchoring; Residual stress; Laser surface texture; Adhesion strength
• ISSN: 0030-3992; 1879-2545
• DOI: 10.1016/j.optlastec.2024.110840

•The square micro-textures inspired by straw checkered sand fixation are fabricated on the SiC substrate using nanosecond laser sculpture.•The square micro-texturesprovide a 200% increase in adhesion strength than the conventional grit-blasted one.•The mechanical anchoring, wetting, and residual stress work synergistically to enable the laser surface texture to exhibit better adhesion on the SiC substrate. In order to enhance the adhesion strength between the Si-HfO2 bond coat and substrate, square micro-textures inspired by straw-checkered sand fixation are fabricated using nanosecond laser sculpture. The adhesion strength of the laser surface texture (LST) sample is up to 27.31 ± 3.34 MPa, which is more than 200 % higher than the conventional grit-blasted one (8.12 ± 0.70 MPa). The promoted interface bonding is attributed to the following three aspects: First, the mechanical anchoring established by micro-texture positively improves the adhesion strength. Second, the LST diminishes the contact angle to 16.5 ± 1.7°, improving the wetting of the SiC substrate. Third, the high-pressure plasma is implemented to produce enormous compressive stress (205.6 ± 14.6 MPa) on the SiC substrate surface, greatly aiding substrate/coating adhesion. The above three mechanisms work synergistically to enable the LST treatment to exhibit better adhesion than the conventional grit-blasted treatment on SiC substrate.