Effect of diffusion time on diffusion behavior of tungsten in TiAl alloy

doi:10.13251/j.issn.0254-6051.2020.11.018

Abstract

Abstract: Effect of holding time on diffusion behavior of tungsten in TiAl alloy under 1250 ℃ was studied by means of OM, SEM, and hardness test. The results show that, the interface between specimens have good combination after diffusion at 1250 ℃ for different time, which shows obvious metallurgical bonding. And the thickness of diffusion layers increases with increasing time, thus the thickness of diffusion layer after diffusion for 4 h is about 15 μm, and that for 24 h is about 45 μm. In addition, the defects such as cracks and pore at the interface can be inhibited by prolonging diffusion time (24 h). The replacement and vacancy diffusion are the main diffusion mechanisms of tungsten in the TiAl alloy, and the W and Ti atoms have some difference on atomic radius and coefficient of thermal expansion, which makes the lattice distort and furtherly prohibits the diffusion of W element. The results of hardness test show that, after diffusion of tungsten in the TiAl alloy, the hardness of TiAl alloy is reinforced, and the value increases with the increase of W contont.

Key words: titanium aluminum alloy, diffusion mechanism, diffusion bonding, tungsten

CLC Number:

TG146

Huang Qingyi, Yi Yuan. Effect of diffusion time on diffusion behavior of tungsten in TiAl alloy[J]. Heat Treatment of Metals, 2020, 45(11): 94-98.

References

[1]Appel F, Wagner R. Microstructure and deformation of two-phase γ-titanium aluminides[J]. Materials Science and Engineering R, 1998, 22(5): 187-268.
[2]冯旭东, 袁庆龙, 曹晶晶, 等. TiAl基合金研究进展[J]. 航天制造技术, 2009(3): 35-38.
Feng Xundong, Yuan Qinglong, Cao Jingjing, et al. Progress in TiAl-based alloys[J]. Aerospace Manufacturing Technology, 2009(3): 35-38.
[3]蔡建明, 李臻熙, 马济民, 等. 航空发动机用600 ℃高温钛合金的研究与发展[J]. 材料导报, 2005, 19(1): 50-53.
Cai Jianming, Li Zhenxi, Ma Jimin, et al. Research and development of 600 ℃ high temperature titanium alloys for aeroengine[J]. Materials Review, 2005, 19(1): 50-53.
[4]王秀锋, 喻更生, 刘学斌, 等. γ-TiAl基合金超塑扩散连接实验与理论的研究[J]. 钛工业进展, 2006, 23(1): 10-15.
Wang Xiufeng, Yu Gengsheng, Liu Xuebin, et al. Experimental and theoretical study of superplastic forming/diffusion bonding in γ-TiAl based alloys[J]. Titanium Industry Progress, 2006, 23(1): 10-15.
[5]罗致春, 王秀锋, 刘学斌, 等. γ-TiAl基合金与异种合金扩散连接研究[J]. 钛工业进展, 2006, 23(6): 20-23.
Luo Zhichun, Wang Xiufeng, Liu Xuebin, et al. Diffusion bonding of γ-TiAl based alloys to different alloys[J]. Titanium Industry Progress, 2006, 23(6): 20-23.
[6]何鹏, 冯吉才, 钱乙余. TiAl/40Cr钢扩散连接界面组织结构对接头强度的影响[J]. 材料科学与工艺, 2003, 11(2): 144-147.
He Peng, Feng Jicai, Qian Yiyu. Effect of interfacial microstructure of TiAl/40Cr diffusion bonding on strength of joint[J]. Materials Science and Technology, 2003, 11(2): 144-147.
[7]李书江, 王艳丽, 林均品, 等. 微量C, B对高铌TiAl合金显微组织与力学性能的影响[J]. 稀有金属材料与工程, 2004, 33(2): 144-148.
Li Shujiang, Wang Yanli, Lin Junpin, et al. Influence of C and B elements on structures and mechanical properties for high Nb containing TiAl alloy[J]. Rare Metal Materials and Engineering, 2004, 33(2): 144-148.
[8]孙红亮, 孙才, 黄泽文, 等. W对含铌TiAl合金组织与力学性能的影响[J]. 热加工工艺, 2011, 40(22): 15-17.
Sun Hongliang, Sun Cai, Huang Zeiwen, et al. Effect of tungsten addition on microstructure and mechanical properties of TiAl-based alloy[J]. Hot Working Technology, 2011, 40(22): 15-17.
[9]Wu Y, Hwang S K, Morris J W. Development and elemental powder metallurgy of a Y-containing two-phase TiAl alloy[J]. Metallurgical and Materials Transactions A, 2003, 34(10): 2077.
[10]张宁, 林均品, 王艳丽, 等. W, B, Y合金元素对高铌TiAl基合金高温长期抗氧化性能的影响[J]. 稀有金属材料与工程, 2007, 36(5): 884-887.
Zhang Ning, Lin Junpin, Wang Yanli, et al. Influence of W, B, and Yelements on antioxidation of high temperature and long term for TiAl based alloys with high Nb content[J]. Rare Metal Materials and Engineering, 2007, 36(5): 884-887.
[11]Shida Y, Anada H. Role of W, Mo, Nb and Si in oxidation of TiAl in air at high temperature[J]. Journal of the Japan Institute of Metals, 1994, 58(7): 754-762.