Comparative study on the effects of α/γ phase ratio on the micro-structures and properties in Al2O3 coatings under silicon ion irradiation. (June 2022)

• Record Type: Journal Article
• Authors: Li, Jia; Pu, Guo; Sun, Haoxin; Yang, Hongzhi; Lin, Liwei; Ren, Ding; Zhang, Kun; Liu, Bo
• Is Part Of: Vacuum. Volume 200(2022)
• Publication Date: 2022-06
• Subjects: Supersonic atmospheric plasma spraying -- Al2O3 tritium permeate barrier -- α/γ phase ratios -- Irradiation tolerance -- Mechanical properties -- Electrochemical corrosion resistance; Vacuum -- Periodicals; 621.55
• DOI: 10.1016/j.vacuum.2022.110988
• Languages: English
• ISSNs: 0042-207X

Abstract

Abstract: In this work, the Al2 O3 tritium permeate barriers (TPBs) with controllable α/γ phase ratios were prepared by supersonic atmospheric plasma spraying. A comparative study was carried out to explore micro-structure, irradiation tolerance, corrosion property and mechanical properties in the Al2 O3 coatings with different α phase ratios (77.6 ± 3.9% and 23.4 ± 1.2%, respectively) irradiated by Si + with fluence from 5 × 10 15 to 5 × 10 16 cm −2 at room temperature. Results indicated a quite stable in crystalline structure and diverse irradiation-defect in two kinds of Al2 O3 coatings after irradiation. The lower corrosion current densities were measured in the higher α phase Al2 O3 coatings before and after Si + irradiation. Also, the vacancy-clusters and dislocations aggregated from point defects are main reasons to explain the increase in mechanical properties at low fluence. The smaller dislocation loops and its less distribution are responsible for the more stable evolution-tendency in hardness and fracture toughness for the higher α phase Al2 O3 coating irradiated at fluence of 5 × 10 16 cm −2 . And this investigation results provide a basic reference for TPBs design by supersonic atmospheric plasma spraying (SAPS) technology for future fusion reactor. Highlights: The Al2 O3 tritium permeate barriers (TPB) with controllable α/γ phase ratios were prepared by SAPS. The diverse defect and its distribution were disclosed in selected Al2 O3 composite coatings with different α phase ratio. High α phase Al2 O3 composite coating exhibits better irradiation resistance and corrosion tolerance. Various evolution tendencies in mechanical properties were revealed in detail.