Research on Interlayer Alloys for Transient Liquid Phase Diffusion Bonding of Single Crystal Nickel Base Superalloy DD6

Qiuya Zhai, Jinfeng Xu, Tianyu Lu, Yan Xu

School of Materials Science and Engineering, Xi'an University of Technology, Xi'an, China.

DOI: 10.4236/msce.2014.29002                

Abstract

Transient Liquid Phase Diffusion bonding (TLP bonding) is an effective method to achieve excellent joint of DD6, which is a new generation single crystal superalloy to manufacture aero-engine turbine blades. In this paper, the interlayer alloys for DD6 TLP bonding were designed. The alloy foils with thickness 40 μm ~ 60 μm, width 4 mm were prepared by using a single roller rapid solidification apparatus and the TLP bonding of DD6 was conducted. Then the joint microstructure and alloying elements diffusion behaviors were analyzed. The results indicate that microstructures of interlayer alloys prepared are fine and homogeneous, the melting point range of alloys from 1070^°C to 1074^°C and their melting temperature interval is merely 20^°C, when the chemical composition of alloys are 1.5 ~ 2.0Cr, 3.2 ~ 4.0W, 3.7 ~ 4.5Co, 2.2 ~ 3.0Al, 0.7 ~ 1.0Mo, 3.2B, remain Ni (wt%). When the welding parameters are bonding temperature 1200?C, holding time 8.0 hour and welding pressure 0.3 MPa, the compacted joints obtained and the microstructure of TLP bonding seams were similar to base metal. The bonding joint is composed of weld center zone, isothermal solidification zone and diffusion-affected zone. Within joint, the elements diffusion is sufficient and borides in the diffusion zone are fewer.

Keywords

Interlayer Alloy, DD6 Single Crystal Superalloy, TLP Bonding, Microstructure of Joint

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Wang, G., Zhang, B.G. and Feng, J.C. (2008) Research Progress in Pepair Welding Technology of Ni-Based Superalloy Blands. Welding & Joining, 1, 20-23.
[2]	Chen, R.Z. (1995) Development Status of Single Crystal Superalloys. Materials Engineering, 8, 83-12.
[3]	Li, X.H., Mao, W., Guo, W.L. and Xie, Y.H. (2005) Transient Liquid Phase Diffusion Bonding of a Single Crystal Superalloy DD6. Transactions of the China Welding Institution, 26, 51-54.
[4]	Pouranvari, M. and Ekrami, A. (2008) Microstructure Development during Transient Liquid Phase Bonding of GTD-111 Nickel-Based Superalloy. Journal of Alloys and Compounds, 641-647.
[5]	Ojo, O.A., Richards, N.L. and Chaturvedi, M.C. (2004) Isothermal Solidification during Transient Liquid Phase Bonding of Inconel 738 Superalloy. Science and Technology of Welding and Jioning, 9, 532-540.
[6]	Zhai, Q.Y., Tong, D.X., Li, W.W. and Gong, S.T. (2009) Preparation and Welding Performance of Amorphous Interlayer Alloys for TLP Bonding. Transactions of the China Welding Institution, 30, 17-20.
[7]	Wang, F.S., Chen, S.J., Gao, Z., Wen, S.L. and Chen, L. (2009) Applications of Transient Liquid-Phase Bonding in Nickel and Nickel-Base Alloy Welding. Electric Welding Machine, 39, 38-42.
[8]	Liu, S., Olsen, D.L. and Martin, G.P. (1991) Modeling of Brazing Processes That Use Coatings. Welding Journal, 70, 207-215.
[9]	Shi, D.K. (2003) Materials Science. Mechanical Industrial Press, Beijing.
[10]	Xu, J.F. and Wei, B.B. (2004) Liquid Phase Flow and Microstructure Formation during Rapid Solidification. Acta Physica Sinica, 53, 160-166.