High temperature micromechanical behavior of Ti2AlN particle reinforced TiAl based composites investigated by in-situ high-energy X-ray diffraction. (15th December 2021)

• Record Type: Journal Article
• Authors: Li, Jinguang; Hu, Rui; Zhou, Mi; Gao, Zitong; Wu, Yulun; Luo, Xian
• Is Part Of: Materials & design. Volume 212(2021)
• Publication Date: 2021-12-15
• Subjects: TiAl matrix composites -- Micromechanical behavior -- High-energy X-ray diffraction -- Load partitioning; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2021.110225
• Languages: English
• ISSNs: 0264-1275

Abstract

Graphical abstract: Highlights: A link between macro/microscopic deformation of Ti2 AlN/TiAl composite was studied. Fiber textures of γ phase formed more earlier than those of H phase. Dislocation slipping and twinning dominated elastic-plastic transformation of matrix. Atomic ripples and interface-dislocation interaction mechanism occurred in H phase. Abstract: The high-temperature compressive property of Ti2 AlN/TiAl composites, which are promising lightweight materials for high-temperature applications, was investigated. In situ high-energy X-ray diffraction (HEXRD) was utilized to analyze the micromechanical behavior at different deformation stages. It is determined {1 1 0}γ fiber texture firstly formed at work hardening stage and {0002}H fiber texture appeared at softening stage. The micro-deformation sequences were related to crystallographic orientations where [2 0 0]//LD, [2 0 2]//LD oriented γ grains were easier to work-hardening while [0 0 2]//LD, [1 1 0]//LD oriented γ grains presented hardening-softening transformation characteristic. The lattice strain wave of [0 0 0 2]//LD oriented H grain reflected an interesting atomic-scale ripples meanwhile [1 0_1 3]//LD oriented H phase presented a unique interface-dislocation mechanism. A significantly higher stress level in H phase demonstrates its strong bearing capacity. Our investigations establish a relationship between macroscopic deformation of composite and the microscopic elastic/plastic deformation of each component meanwhile provide in-depth understanding of the cooperative deformation characteristics in Ti2 AlN/TiAl composites.