具有网络微观结构的TiBw/Ti6Al4V复合材料上热浸铝涂层的循环氧化行为及抗氧化机制

Cycle oxidation behavior and anti-oxidation mechanism of hot-dipped aluminum coating on TiBw/Ti6Al4V composites with network microstructure.

作者信息

Li X T, Huang L J, Wei S L, An Q, Cui X P, Geng L

机构信息

Key Laboratory of Advanced Structural-Functional Integration Materials & Green Manufacturing Technology, School of Materials Science and Engineering, Harbin Institute of Technology, Harbin, 150001, P.R. China.

State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, P.O. Box 433, Harbin, 150001, P.R. China.

出版信息

Sci Rep. 2018 Apr 10;8(1):5790. doi: 10.1038/s41598-018-24242-0.

DOI:10.1038/s41598-018-24242-0

PMID:29636504

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC5893551/

Abstract

Controlled and compacted TiAl coating was successfully fabricated on the network structured TiBw/Ti6Al4V composites by hot-dipping aluminum and subsequent interdiffusion treatment. The network structure of the composites was inherited to the TiAl coating, which effectively reduces the thermal stress and avoids the cracks appeared in the coating. Moreover, TiB reinforcements could pin the TiAl coating which can effectively improve the bonding strength between the coating and composite substrate. The cycle oxidation behavior of the network structured coating on 873 K, 973 K and 1073 K for 100 h were investigated. The results showed the coating can remarkably improve the high temperature oxidation resistance of the TiBw/Ti6Al4V composites. The network structure was also inherited to the AlO oxide scale, which effectively decreases the tendency of cracking even spalling about the oxide scale. Certainly, no crack was observed in the coating after long-term oxidation due to the division effect of network structured coating and pinning effect of TiB reinforcements. Interfacial reaction between the coating and the composite substrate occurred and a bilayer structure of TiAl/TiAl formed next to the substrate after oxidation at 973 K and 1073 K. The anti-oxidation mechanism of the network structured coating was also discussed.

摘要

通过热浸铝及后续的互扩散处理，在网络结构的TiBw/Ti6Al4V复合材料上成功制备了可控且致密的TiAl涂层。复合材料的网络结构被继承到TiAl涂层中，这有效地降低了热应力并避免了涂层中出现裂纹。此外，TiB增强相可以固定TiAl涂层，从而有效提高涂层与复合基体之间的结合强度。研究了网络结构涂层在873K、973K和1073K下100h的循环氧化行为。结果表明，该涂层能显著提高TiBw/Ti6Al4V复合材料的高温抗氧化性能。网络结构也被继承到AlO氧化膜中，这有效地降低了氧化膜开裂甚至剥落的倾向。当然，由于网络结构涂层的分割作用和TiB增强相的固定作用，长期氧化后涂层中未观察到裂纹。在973K和1073K氧化后，涂层与复合基体之间发生了界面反应，在基体附近形成了TiAl/TiAl双层结构。还讨论了网络结构涂层的抗氧化机理。