Highly oxidation-resistant Ti-Mo alloy with two-scale network Ti_(5)Si_(3)reinforcement

作     者：Qiong Lu Yaozha Lv Chi Zhang Hongbo Zhang Wei Chen Zhanyuan Xu Peizhong Feng Jinglian Fan Qiong Lu;Yaozha Lv;Chi Zhang;Hongbo Zhang;Wei Chen;Zhanyuan Xu;Peizhong Feng;Jinglian Fan

作者机构：Powder Metallurgy Research InstituteCentral South UniversityChangsha 410083China Department of Mechanical EngineeringImperial College LondonExhibition RoadLondon SW72AZUK School of Materials Science and EngineeringChina University of Mining and TechnologyXuzhou 221116China 

出 版 物：《Journal of Materials Science & Technology》 (材料科学技术（英文版）)

年 卷 期：2022年第110卷第15期

页      面：24-34页

核心收录：

学科分类：08[工学] 0806[工学-冶金工程] 0804[工学-仪器科学与技术] 0805[工学-材料科学与工程（可授工学、理学学位）] 0703[理学-化学] 

基　　金：financially supported by the National Natural Science Foundation of China(NSFC)[Grant No.51534009] National Key R&D Program of China[Grant No.2017YFB0306001] Natural Science Foundation of Hunan Province China(Grant No.2021JJ40750)。 

主　　题：Ti matrix composites Oxidation mechanism Thermal stability Interface strengthening Transmission electron microscopy 

摘      要：There is keen interest in using Ti alloys as lightweight structural materials for aerospace and automotive industries.However,a long-standing problem for these materials is their poor oxidation resistance.Herein,we designed and fabricated a Ti_(5)Si_(3) reinforced Ti-4(wt.%)Mo composite with two-scale network architecture by low energy milling and spark plasma sintering.It displays superior oxidation resistance at 800°C owing to the in-situ formation of a multi-component surface layer.This oxide layer has a dense grain size gradient structure that consists of an outer TiO_(2)layer and an inner SiO_(2)-padding-TiO_(2) layer,which has remarkable oxidation resistance and thermal stability.Furthermore,it was revealed that the hitherto unknown interaction between Ti_(5)Si_(3) reinforcement and nitrogen during oxidation would contribute to the formation of a TiN nano-twin interface layer,which accommodates the thermal mismatch strain between the oxide layer and matrix.This,along with high adhesion,confers excellent thermal cycling life with no cracking or spallation during long-term oxidation.In this regard,the secure operating temperature of this new composite can be increased to 800°C,which provides a design pathway for a new family of Ti matrix composites for high-temperature applications.