Interfacial Reaction of SiC_f/TiAl Composites Dominated by Mo Interfacially Modified Layer AITranslate

［1］Guo S Q，Kagawa Y，Saito H，Masuda C. Microstructural characterization of interface in SiC fiber-reinforced Ti-15V-3Cr-3Al-3Sn matrix composite ［J］. Materials Science and Engineering A，1998，246（1–2）：25.

［2］Zhao G M，Yang Y Q，Zhang W，Luo X，Huang B，Chen Y. Microstructure and grain growth of the matrix of SiCf/Ti–6Al–4V composites prepared by the consolidation of matrix-coated fibers in the β phase field ［J］. Composites Part B：Engineering，2013，52：155.

［3］（黄浩，王敏涓，李虎，李四青，张书铭，李臻熙，黄旭，解川. 连续SiC纤维增强钛基复合材料研制 ［J］. 航空制造技术，2018，61（14）：26.）

H Huang，M J Wang，H Li，S Q Li，S M Zhang，Z X Li，X Huang，C Xie. Preparation of SiC fibers reinforced titanium matrix composites ［J］. Aeronautical Manufacturing Technology，2018，61（14）：26.

［4］（王敏涓，黄浩，王宝，韩波，杨平华，黄旭. 连续SiC纤维增强钛基复合材料应用及研究进展 ［J］. 航空材料学报，2023，43（6）：1.）

M J Wang，H Huang，B Wang，B Han，P H Yang，X Huang. Application and research progress of continuous SiC fiber reinforced titanium matrix composite materials ［J］. Journal of Aeronautical Materials，2023，43（6）：1.

［5］（王玉敏，张国兴，张旭，杨青，杨丽娜，杨锐. 连续SiC纤维增强钛基复合材料研究进展 ［J］. 金属学报，2016，52（10）：1153.）

Y M Wang，G X Zhang，X Zhang，Q Yang，L N Yang，R Yang. Advances in SiC fiber reinforced titanium matrix composites ［J］. Acta Metallurgica Sinica，2016，52（10）：1153.

［6］（纪福森，徐磊. 连续纤维增强钛基复合材料整体叶环设计与分析 ［J］. 航空发动机，2017，43（6）：21.）

F S Ji，L Xu. Design and analysis continuous fiber reinforced TMC bling ［J］. Aeroengine，2017，43（6）：21.

［7］Chen G，Peng Y，Zheng G，Qi Z X，Wang M Z，Yu H C. Polysynthetic twinned TiAl single crystals for high-temperature applications ［J］. Nature Materials，2016，15（8）：876.

［8］Tan Y M，Chen R R，Fang H Z，Liu Y L，Ding H S，Su Y Q，Guo J J，Fu H Z. Microstructure evolution and mechanical properties of TiAl binary alloys added with SiC fibers ［J］. Intermetallics，2018，98：69.

［9］Djanarthany S，Viala J C，Bouix J. Development of SiC/TiAl composites：processing and interfacial phenomena ［J］. Materials Science and Engineering：A，2001，300（1）：211.

［10］Wagner R，Appel F. Microstructure and deformation of two-phase γ-titanium aluminides ［J］. Materials Science and Engineering，1998，R22：187.

［11］Zhou F H，Hashimoto R，Ogawa A，Sofue Y. Residual stress and its effect on yielding in SiC/Ti plate ［J］. JSME International Journal Series A Solid Mechanics and Material Engineering，2006，49（1）：25.

［12］Bobet J L，Masuda C. Measurements of thermal residual stresses in SiC/Ti-15–3 composites ［J］. Journal of Thermal Stresses，1996，19（6）：579.

［13］（吕毅，张伟，吕鹏. 界面层对C/SiC复合材料热残余应力影响的模拟及分析 ［J］. 机械科学与技术，2018，37（6）：949.）

Y Lv，W Zhang，P Lv. Simulation and analysis of influence of interface on thermal residual stress of C/SiC composites ［J］. Mechanical Science and Technology for Aerospace Engineering，2018，37（6）：949.

［14］Lü X H，Yang Y Q，Ma Z J，Chen Y. Studies on the behaviors of interfacial reaction diffusion of SiC continuous fiber-reinforced Ti matrix composites ［J］. Rare Metal Materials and Engineering，2006，35（1）：164.

［15］Zhao Y Q，Zhou L，Vassel A，Zeng L Y，Qu F L，Mao X N. Study of interfaces in titanium alloy composites reinforced with continuous SiC fibers ［J］. Rare Metal Materials and Engineering，2004，33（4）：359.

［16］Fu Y C，Shi N L，Zhang D Z，Yang R. Effect of C coating on the interfacial microstructure and properties of SiC fiber-reinforced Ti matrix composites ［J］. Materials Science and Engineering：A，2006，426（1–2）：278.

［17］Li X Y，Zhang W. Interfacial reaction in SiCf/C/TiAl matrix composites ［J］. Journal of Materials Research and Technology，2021，12：1227.

［18］（王敏涓，陈永刚，高帆，李虎，黄旭，黄浩. SiC纤维增强TiAl基复合材料残余应力的调控 ［J］. 稀有金属，2023，47（6）：787.）

M J Wang，Y G Chen，F Gao，H Li，X Huang，H Huang. Regulation of residual stress in SiC fiber reinforced TiAl matrix composites ［J］. Chinese Journal of Rare Metals，2023，47（6）：787.

［19］Wu M，Zhang K，Huang H，Wang M J，Li H，Zhang S M，Wen M. Interfacial reactions in SiCf/C/Ti17 composites dominated by texture of carbon coatings ［J］. Carbon，2017，124：238.

［20］Zhu T K，Wang D G，Luo X. Effect of C/Mo duplex-coating on thermal residual stresses in SiCf/Ti2AlNb composites ［J］. Journal of Wuhan University of Technology-Mater. Sci. Ed.，2021，36（4）：526.

［21］Luo X，Yang Y Q，Yu Y J，Wang X R，Huang B，Chen Y. Effect of Mo coating on the interface and mechanical properties of SiC fiber reinforced Ti6Al4V composites ［J］. Materials Science and Engineering：A，2012，550：286.

［22］Wang X R，Yang Y Q，Luo X，Zhang W，Jin N，Xiao Z Y，Feng G H. Effect of C/Mo duplex coating on the interface and mechanical properties of SiCf/Ti6Al4V composites ［J］. Materials Science and Engineering：A，2013，566：47.

［23］（胡锐，李劲光，周咪，罗贤. TiAl合金复合韧化及其复合材料研究进展 ［J］. 精密成形工程，2022，14（11）：133.）

R Hu，J G Li，M Zhou，X Luo. Recent advance on toughening of TiAl composite and TiAl matrix composites ［J］. Journal of Netshape Forming Engineering，2022，14（11）：133.

［24］Qiu C Z，Liu Y，Huang L，Zhang W，Liu B，Lu B. Effect of Fe and Mo additions on microstructure and mechanical properties of TiAl intermetallics ［J］. Transactions of Nonferrous Metals Society of China，2012，22（3）：521.

［25］Luo X，Li C，Yang Y Q，Xu H M，Li X Y，Liu S，Li P T. Microstructure and interface thermal stability of C/Mo double-coated SiC fiber reinforced γ-TiAl matrix composites ［J］. Transactions of Nonferrous Metals Society of China，2016，26（5）：1317.

［26］Hirsch F，Natkowski E，Kästner M. Modeling and simulation of interface failure in metal-composite hybrids ［J］. Composites Science and Technology，2021，214：108965.

［27］Brendel A，Popescu C，Leyens C，Woltersdorf J，Pippel E，Boit H. SiC-fibre reinforced copper as heat sink material for fusion applications ［J］. Journal of Nuclear Materials，2004，329–333：804.

［28］Rado C，Drevet B，Eustathopoulos N. The role of compound formation in reactive wetting：the Cu/SiC system ［J］. Acta Materialia，2000，48（18–19）：4483.

［29］（叶滨，吕会议，陈青云，刘绪海，杨桃，苟彬彬，许文博，袁欢，徐明. MAX相金属陶瓷材料研究进展与展望 ［J］. 西南民族大学学报（自然科学版），2021，47（1）：83.）

B Ye，H Y Lv，Q Y Chen，X H Liu，T Yang，B B Gou，W B Xu，H Yuan，M Xu. Research progress and prospect of MAX phase ceramic ［J］. Journal of Southwest Minzu University （Natural Science Edition），2021，47（1）：83.

［30］Nicolaï J，Furgeaud C，Fonrose B W，Bail C，Beaufort M F. Formation mechanisms of Ti2AlC MAX phase on SiC-4H using magnetron sputtering and post-annealing ［J］. Materials & Design，2018，144：209.

［31］Shen J B，Zhang M，Lin S，Song W H，Liu H J，Liu Q C，Zhu X B. High-entropy enhanced microwave absorption in MAX phases ［J］. Journal of Applied Physics，2023，133（23）：235101.

Basic Information:

DOI：10.13373/j.cnki.cjrm.XY24100011

Chinese Library Classification Number:TB333

Citation Information:

The advantages of SiC fiber reinforced titanium-aluminium （SiC_f/TiAl） composites，such as low density，high strength and high stiffness at high temperatures，have made them a much-needed high-temperature resistant，lightweight and high-strength structural material for aerospace applications. However，the TiAl matrix has low ductility at room temperature and reacts with SiC fibres to form a brittle interfacial reaction layer that can easily become a source of cracks and induce brittle fracture，which severely limits the improvement of mechanical strength of SiC_f/TiAl composites. In this work，SiC_f/C/Mo/TiAl composite was prepared by introducing Mo interfacial modification layer on C-coated SiC fibres by physical vapor deposition （PVD） technique，and their interfacial reaction and TiAl matrix near the interface were modulated to achieve the purpose of strengthening and toughening. Firstly，transmission electron microscope （TEM） was used to identify the products of interfacial reaction layer in both SiC_f/C/TiAl and SiC_f/C/Mo/TiAl composites，and then their interfacial reaction mechanism was thoroughly investigated. It was found that SiC_f/C/TiAl composites formed an interfacial reaction layer of ~2 μm thickness due to the interdiffusion of C and Ti during high-temperature consolidation，and the generation sequence of the reaction products was nanocrystalline TiC mixed with C/fine-crystalline TiC layer/coarse-crystalline TiC+Ti₂AlC MAX phase. This interfacial composition could be well explained by the diffusion-solid solution reaction mechanism，where the formation of the interfacial reaction layer was caused by the mutual diffusion of Ti and C. The diffusion rate of C into TiAl matrix was much larger than that of Ti into C coating，where the diffusion of Ti into C coating led to diffuse aggregation of Ti in C tissue，and the formation of nanocrystalline TiC and C mixed zones with a thickness of only a few tens of nanometers. At the same time，C would also diffuse toward TiAl matrix，which would produce a gradient distribution of C content along the diffusion path. In the early reaction period，C content was sufficient，Ti preferentially reacted with C for a rapid nucleation，forming fine-crystalline TiC layer. After formation of a continuous layer of fine-crystalline TiC，C was going to diffuse through TiC layer by bulk diffusion and continue to react with TiAl matrix. At this time，the grain size of TiAl matrix grew rapidly，and when C entered，two reactions occurred，Ti+C=TiC and 2Ti+Al+C=Ti₂AlC，but Ti₂AlC MAX phase was more likely to be formed，resulting in RL 3 layer mainly consisting of Ti₂AlC MAX phases with Ti-C-Ti-Al stacked structure. When the grain size of the reactive layer close to the TiAl matrix size was larger，it was more difficult to form an ordered stacking of Ti-C-Ti-Al stacking structure，and it was more likely to exist as a Ti（Al）C solid solution phase；therefore，the reaction layer of coarse crystals mainly consisted of Ti₂AlC MAX phase+TiC with large size. The generation of brittle reaction layer led to the tensile properties of SiC_f/C/TiAl composites to be significantly lower than those of SiC_f/C/Mo/TiAl composites. The tensile tests and fracture observations showed that SiC_f/C/TiAl composite exhibited typical brittle fracture and low tensile strength （675 MPa） accompanied by the appearance of penetrating cracks. As for SiC_f/C/Mo/TiAl composite，Mo was introduced as a toughened modified layer between C coating and TiAl matrix. Only a few tens of nanometer thick MoC+Mo₂C reaction layer was formed in SiC_f/C/Mo/TiAl composite，which was much thinner than SiC_f/TiAl composite. The addition of Mo interface modification layer not only inhibited the formation of too thick brittle carbide reaction layer，but also induced the formation of high-toughness β-Ti layer and Al gradient variation TiAl layer in the region near Mo layer，avoiding the interfacial stress concentrations and appearance of cracks under tensile loading，thereby realizing toughening. Through the tensile test and fracture observation，it could be found that the introduction of Mo interfacially modified layer made the penetrating crack disappear in SiC_f/C/Mo/TiAl composite and promoted the fiber pullout phenomenon，and the appropriate interface debonding and fiber pullout could greatly improve the tensile strength of the composites，so that the tensile strength of SiC_f/C/Mo/TiAl composite at 800 ℃ was increased to 1040 MPa.