From crack-prone to crack-free: Unravelling the roles of LaB6 in a β-solidifying TiAl alloy fabricated with laser additive manufacturing

Huang，Danni1,2; Zhou，Yinghao2; Yao，Xiyu2; Tan，Qiyang1; Chang，Haiwei1; Wang，Dawei2; Lu，Songhe2; Liu，Shiyang1; Xu，Jingyuan1,2; Jin，Shenbao3; Sha，Gang3; Huang，Han1; Yan，Ming2,4; Zhang，Ming Xing1

2022-12-19

10.1016/j.msea.2022.144358

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING   Impact Factor & Quartile

0921-5093

1873-4936

The 4th generation of intermetallic γ-TiAl based alloy, the so-called β-solidifying TiAl, has attracted great attentions due to its promising high-temperature properties. But it is intrinsically brittle and crack-prone, which lowers the processability of laser additive manufacturing (LAM) that offers an effective pathway for material processing and design. Thus, improving the mechanical properties, particularly the room temperature plasticity, of LAMed β-solidifying TiAl alloy is of technical interest and theoretical importance. Based on previous results, the present work investigates the synergistic roles of La and B in grain refinement and crack elimination in a LAMed β-solidifying TiAl alloy with LaB addition (0–2 wt%). Results show that LaO and TiB in-situ formed via reaction between the β-solidifying TiAl and the added LaB nanoparticles. Microstructural feature, phase transformation texture and mechanical properties at both room and high temperatures can be optimized through controlling the LaB addition level. 0.5 wt% LaB has been determined as the optimized addition, at which the balanced mechanical properties at both room temperature and 800 °C can be achieved for the LAMed β-solidifying TiAl alloy. Excessive LaB addition led to agglomeration of in-situ formed precipitates, reducing density and therefore deteriorating mechanical properties. The study offers an in-depth understanding of the effective grain refining approach to overcome the intrinsic brittle nature of β-solidifying TiAl through optimized doping of LaB.

Additive manufacturing Mechanical properties Phase transformation β-solidifying TiAl alloy

SCI

English

Corresponding

Natural Science Foundation of Guangdong Province[2020A1515011373];National Natural Science Foundation of China[51971108];National Natural Science Foundation of China[52271032];

Science & Technology - Other Topics ; Materials Science ; Metallurgy & Metallurgical Engineering

Nanoscience & Nanotechnology ; Materials Science, Multidisciplinary ; Metallurgy & Metallurgical Engineering

WOS:000934008300001

ELSEVIER SCIENCE SA

MATERIALS SCIENCE

2-s2.0-85142363523

Scopus

1.School of Mechanical and Mining Engineering,The University of Queensland,St. Lucia,4072,Australia
2.Department of Materials Science and Engineering and Shenzhen Key Laboratory for Additive Manufacturing of High-performance Materials,Southern University of Science and Technology,Shenzhen,518055,China
3.Herbert Gleiter Institute of Nanoscience,School of Material Science and Engineering,Nanjing University of Science and Technology,Nanjing,210094,China
4.Jiaxing Research Institute,Southern University of Science and Technology,Jiaxing,314031,China

Huang，Danni,Zhou，Yinghao,Yao，Xiyu,et al. From crack-prone to crack-free: Unravelling the roles of LaB6 in a β-solidifying TiAl alloy fabricated with laser additive manufacturing[J]. MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING,2022,861.

Huang，Danni.,Zhou，Yinghao.,Yao，Xiyu.,Tan，Qiyang.,Chang，Haiwei.,...&Zhang，Ming Xing.(2022).From crack-prone to crack-free: Unravelling the roles of LaB6 in a β-solidifying TiAl alloy fabricated with laser additive manufacturing.MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING,861.

Huang，Danni,et al."From crack-prone to crack-free: Unravelling the roles of LaB6 in a β-solidifying TiAl alloy fabricated with laser additive manufacturing".MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING 861(2022).