The improved properties and microstructure of β-solidify TiAl alloys by boron addition and multi steps forging process

Shulong Xiao; Yuyong Chen; Mingao Li; Lijuan Xu; Jing Tian; Dongdong Zhang; Jianhui Yang

doi:10.1038/s41598-019-47530-9

The improved properties and microstructure of β-solidify TiAl alloys by boron addition and multi steps forging process

Sci Rep. 2019 Aug 27;9(1):12393. doi: 10.1038/s41598-019-47530-9.

Authors

Shulong Xiao^{1

2}, Yuyong Chen^{3

4}, Mingao Li^{5

6}, Lijuan Xu², Jing Tian², Dongdong Zhang^{1

2}, Jianhui Yang^{1

2}

Affiliations

¹ National Key Laboratory for Precision Hot Processing of Metals, Harbin Institute of Technology, Harbin, 150001, P.R. China.
² School of Materials Science and Engineering, Harbin Institute of Technology, Harbin, 150001, P.R. China.
³ National Key Laboratory for Precision Hot Processing of Metals, Harbin Institute of Technology, Harbin, 150001, P.R. China. yychen@hit.edu.cn.
⁴ School of Materials Science and Engineering, Harbin Institute of Technology, Harbin, 150001, P.R. China. yychen@hit.edu.cn.
⁵ National Key Laboratory for Precision Hot Processing of Metals, Harbin Institute of Technology, Harbin, 150001, P.R. China. limingao1122@outlook.com.
⁶ School of Materials Science and Engineering, Harbin Institute of Technology, Harbin, 150001, P.R. China. limingao1122@outlook.com.

Abstract

A novel forging process has been designed for better mechanical properties of Ti-43Al-6Nb-1Mo-1Cr-(0,0.6)B alloys in this paper. Multi step forging process could provide much finer microstructure, higher room-temperature strength, increased high-temperature strength and elongation with these alloys. The forged alloys without boron exhibit strength and elongation as 676.05 ± 11.37 MPa and 41.32 ± 1.38% at 800 °C, while the average grain size represents as 12.63 ± 3.77 μm. The forged alloys with 0.6 at.% B represent better mechanical properties than the forged alloys without boron, due to the refined microstructure with dispersive borides. Meanwhile, the detailed mechanism of increased strength and elongation caused by finer microstructure were concluded and discussed.