A chemo-thermo-mechanically constitutive theory of high-temperature interfacial oxidation in alloys under deformation  

作　　者：ZHOU QianQian YANG Li NIE Min ZHOU YiChun WEI YueGuang 

机构地区：[1]College of Engineering,BIC-ESAT,Peking University,Xi'an 710126,China [2]School of Advanced Materials and Nanotechnology,Xidian University,Beijing 100871,China [3]Frontier Research Center of Thin Films and Coatings for Device Applications,Academy of Advanced Interdisciplinary Research,Xidian University,Xi'an 710126,China [4]AECC Hunan Aviation Powerplant Research Institute,Zhuzhou 412002,China

出　　处：《Science China(Technological Sciences)》2023年第4期1018-1037,共20页中国科学（技术科学英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.11890684,12032001,and 51590891);the Technology Innovation Leading Program of Shaanxi(Grant No.2022TD-28);the Hunan Provincial Natural Science Innovation Research Group Fund(Grant No.2020JJ1005)。

摘　　要：Failure due to interfacial oxidation is one of the most important factors in the failure of alloy systems at high temperatures.To analyze high-temperature interfacial oxidation in alloys under deformation,we develop a thermodynamically consistent continuum theory of alloy interfacial oxidation process considering diffusion,oxidation,expansion,viscoplasticity,and deformation processes.Balance equations of force,mass,and energy are presented at first,while the coupled constitutive laws and evolution equations are constructed according to energy dissipation inequality.The coupled kinetics reveals a new mechanism whereby deformation affects the oxidation reaction by changing the alloy’s critical oxygen concentration.External tensile loads decrease the critical oxygen concentration and promote oxidation of the alloy.Conversely,external compressive loads increase the critical oxygen concentration and suppress the oxidation of the alloy.Finally,this theory is applied to thermal barrier coatings(TBCs),exhibiting a good consistency with the high-temperature oxidation experiment of TBCs under external loads.The model successfully explains that the experimental phenomenon of external tensile load accelerates the growth of Al_(2)O_(3)-TGO(thermally grown oxides).Besides,external compressive loads slow down the growth of Al_(2)O_(3)-TGO at the interface and lead to internal oxidation of the bond coat.The presented framework has shown great potential for modeling high-temperature interfacial oxidation processes in alloy systems under deformation.

关 键 词：THERMODYNAMICS OXIDATION oxygen diffusion chemo-thermo-mechanically coupling alloy 

分 类 号：TG131[一般工业技术—材料科学与工程]