Microstructure evolution and tensile property of TiAl alloy using continuous direct energy deposition technique

被引:17
作者
Cheng, Fang [1 ,3 ]
Wang, Huaming [1 ,2 ,3 ,4 ]
Wu, Yu [1 ,3 ]
Ma, Xingjia [1 ,3 ]
Wang, Jiawei [1 ,3 ]
Yang, Junwei [1 ,3 ]
Cheng, Xu [1 ,2 ,3 ,4 ]
机构
[1] Beihang Univ, Sch Mat Sci & Engn, 37 Xueyuan Rd, Beijing, Peoples R China
[2] Beihang Univ, Res Inst Frontier Sci, Beijing 100191, Peoples R China
[3] Beihang Univ, Natl Engn Lab Addit Mfg Large Metall Components, Beijing 100191, Peoples R China
[4] Beihang Univ, Ningbo Inst Technol, Ningbo 315800, Peoples R China
关键词
Continuous direct energy deposition technique; TiAl alloy; Microstructure evolution; Tensile property; MECHANICAL-PROPERTIES; PHASE-TRANSFORMATION; HEAT-TREATMENT; PARAMETERS; GAMMA; TEXTURE; CAST;
D O I
10.1016/j.jallcom.2022.164309
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
Attributing to the fast solidification and thermal cycling during additive manufacturing process, massive phase transformation could take place thus leading to the formation of unpredictable microstructures with large variation in mechanical properties. In this paper, a continuous direct energy deposition technique (CDED) is adopted to prepare TiAl alloy seceding from the thermal cycling, and the evolution of micro-structure, microhardness and tensile properties of alloy are investigated. Results indicate that the micro-structure of alloy composes of columnar grains with very fine (alpha 2 +gamma) lamellae, and no heat-affect band is observed. A heat transfer model is established to assist in explaining the solid-phase transformation and microstructure formation mechanism of TiAl alloy. Furthermore, a special duplex gamma microstructure (DP gamma) forms which composes of massive gamma phase surrounded by feathery-like gamma phase. By dissecting crystallographic orientation from EBSD results, the formation mechanism of DP gamma is clarified as the result of sequential solid-state phase transition in (alpha + gamma) phase region, in which the feathery-like microstructure forms firstly followed by the massive gamma phases nucleating at the inter-phase boundaries of feathery-like gamma. Tensile property of as-deposited alloy reveals of 535 MPa with 1% elongation, and the highest hardness of around 320HV is detected at the top region of alloy with the finest interlamellar spacing. (C) 2022 Elsevier B.V. All rights reserved.
引用
收藏
页数:9
相关论文
共 32 条
[21]   The effect of process parameters and heat treatment on the microstructure of direct laser fabricated TiAl alloy samples [J].
Srivastava, D ;
Chang, ITH ;
Loretto, MH .
INTERMETALLICS, 2001, 9 (12) :1003-1013
[22]   Effect of Mg on the microstructure and properties of TiAl alloys [J].
Sun, FS ;
Froes, FH .
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, 2003, 345 (1-2) :255-261
[23]   Laser Metal Deposition of the Intermetallic TiAl Alloy [J].
Thomas, Marc ;
Malot, Thierry ;
Aubry, Pascal .
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE, 2017, 48A (06) :3143-3158
[24]   Effect of building direction on the microstructure and tensile properties of Ti-48Al-2Cr-2Nb alloy additively manufactured by electron beam melting [J].
Todai, Mitsuharu ;
Nakano, Takayoshi ;
Liu, Tianqi ;
Yasuda, Hiroyuki Y. ;
Hagihara, Koji ;
Cho, Ken ;
Ueda, Minoru ;
Takeyama, Masao .
ADDITIVE MANUFACTURING, 2017, 13 :61-70
[25]   Microstructure characteristics and failure mechanisms of Ti-48Al-2Nb-2Cr titanium aluminide intermetallic alloy fabricated by directed energy deposition technique [J].
Wang, Jiawei ;
Luo, Qian ;
Wang, Huaming ;
Wu, Yu ;
Cheng, Xu ;
Tang, Haibo .
ADDITIVE MANUFACTURING, 2020, 32
[26]   Influence of Mn addition on the microstructure and mechanical properties of a directionally solidified γ-TiAl alloy [J].
Wang, Qiang ;
Ding, Hongsheng ;
Zhang, Hailong ;
Chen, Ruirun ;
Guo, Jingjie ;
Fu, Hengzhi .
MATERIALS CHARACTERIZATION, 2018, 137 :133-141
[27]  
Wu Y., 2020, ADV ENG MATER, V22
[28]   Fabrication of TiAl alloy with no multiple heat-affected bands using continuous direct energy deposition [J].
Wu, Yu ;
Wang, Huaming ;
Ma, Xingjia ;
Wang, Jiawei ;
Cheng, Fang ;
Han, Jiaxing ;
Cheng, Xu ;
Li, An ;
He, Bei .
MATERIALS LETTERS, 2020, 281
[29]   Investigation on solid-state phase transformation in a Ti-47Al-2Cr-2V alloy due to thermal cycling during laser additive manufacturing process [J].
Wu, Yu ;
Zhang, Shuquan ;
Cheng, Xu ;
Wang, Huaming .
JOURNAL OF ALLOYS AND COMPOUNDS, 2019, 799 :325-333
[30]  
Yamaguchi M., 2000, INTERMETALLICS