Mechanical Properties and Damage Tolerance of Bulk Yb3Al5O12 Ceramic
来源期刊:JOURNAL OF MATERIALS SCIENCE TECHNOLOG2015年第4期
论文作者:Xiaofei Wang Huimin Xiang Xin Sun Jiachen Liu Feng Hou Yanchun Zhou
文章页码:369 - 374
摘 要:Yb3Al5O12 has potential applications as thermal barrier coatings(TBCs) because it shows low thermal conductivity and close thermal expansion coefficient to nickel-based superalloys.As a prospective TBC material,besides superior thermal properties,the mechanical properties are also important.In this paper,we present the mechanical properties of Yb3Al5O12 including elastic moduli,hardness,strength,and fracture toughness.The Young’s modulus of Yb3Al5O12 is 282 GPa.The shear-modulus-to-bulkmodulus ratio of Yb3Al5O12 is 0.63,which indicates relatively low shear deformation resistance.In addition,Yb3Al5O12 exhibits high strength and fracture toughness but low hardness compared to yttria stabilized zirconia(YSZ),the most successful TBC material.SEM observation reveals that the fracture surface of Yb3Al5O12 displays "layered structure feature",which is caused by crack deflection.Investigation based on Hertzian contact test demonstrates that Yb3Al5O12 is a damage-tolerant ceramic.Crack deflection and bridging can arouse shear faults,dissipate the local damage energy,and restrict the crack propagation within the material,which play an important role in enhancing the damage tolerance.The superior mechanical properties and good damage tolerance ensure Yb3Al5O12 a promising candidate for TBC applications.
Xiaofei Wang1,2,Huimin Xiang1,Xin Sun1,Jiachen Liu2,Feng Hou2,Yanchun Zhou1
1. Science and Technology of Advanced Functional Composite Laboratory,Aerospace Research Institute of Materials and Processing Technology2. Key Laboratory of Advanced Ceramics and Machining Technology of Ministry of Education,School of Materials Science and Engineering,Tianjin University
摘 要:Yb3Al5O12 has potential applications as thermal barrier coatings(TBCs) because it shows low thermal conductivity and close thermal expansion coefficient to nickel-based superalloys.As a prospective TBC material,besides superior thermal properties,the mechanical properties are also important.In this paper,we present the mechanical properties of Yb3Al5O12 including elastic moduli,hardness,strength,and fracture toughness.The Young’s modulus of Yb3Al5O12 is 282 GPa.The shear-modulus-to-bulkmodulus ratio of Yb3Al5O12 is 0.63,which indicates relatively low shear deformation resistance.In addition,Yb3Al5O12 exhibits high strength and fracture toughness but low hardness compared to yttria stabilized zirconia(YSZ),the most successful TBC material.SEM observation reveals that the fracture surface of Yb3Al5O12 displays "layered structure feature",which is caused by crack deflection.Investigation based on Hertzian contact test demonstrates that Yb3Al5O12 is a damage-tolerant ceramic.Crack deflection and bridging can arouse shear faults,dissipate the local damage energy,and restrict the crack propagation within the material,which play an important role in enhancing the damage tolerance.The superior mechanical properties and good damage tolerance ensure Yb3Al5O12 a promising candidate for TBC applications.
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