Design of novel NiSiAlY alloys in marine salt-spray environment:Part Ⅱ.Al-Ni-Si-Y thermodynamic dataset

• 作者: Kai Xu Keke Chang Miao Yu Dapeng Zhou Yong Du Liping Wang
• 来源期刊: 材料科学技术（英文版）
• 年，卷（期）: 2021,（30）
• 页码范围: 186-198
• 页数: 13页
• 语种: 英文

摘要

The NiSiAlY material is a promising candidate to replace NiCrAlY,which can withstand the harsh salt-spray conditions in marine environment.To efficiently design novel NiSiAlY alloys,this work establishes a thermodynamic dataset of the Al-Ni-Si-Y quaternary system using the CALPHAD (CALculation of PHAse Diagrams) approach.We employ this database to calculate and predict the phase constitutions and solid-ification behaviors of different NiSiAlY alloys concerning the content variations of Al and Si.We have further proposed the selection of the NiSiAlY alloys for serving in marine salt-spray environment with three constraints:(i) outstanding mechanical property;(ii) good high-temperature anti-oxidation;(iii)excellent corrosion resistance.This results in a compositional range of the NiSiAlY alloys with 1 wt％＜ w(Si) ＜ 5 wt％,11 wt％ ＜ w(Al) ＜ 20 wt％ and w(Y) =1 wt％,which corresponds the L12+bcc_B2+Ni5Y ternary phase region at temperatures ranging from ～500 to ～1000 ℃.Our predictions are validated by key experiments,suggesting that the model-based description of the Al-Ni-Si-Y system can serve as a guidance to design the novel NiSiAlY alloys in resisting harsh salt-spray environment.