|
|
|
| FACTORS INFLUENCED INCIPIENT MELTING IN Hf-BEARING DS Ni-BASE SUPERALLOYS |
| by ZHENG Yunrong; CAI Yulin; WANG Luobao (Institute of Aeronautical Materials; Beijing) |
|
Cite this article:
by ZHENG Yunrong; CAI Yulin; WANG Luobao (Institute of Aeronautical Materials; Beijing). FACTORS INFLUENCED INCIPIENT MELTING IN Hf-BEARING DS Ni-BASE SUPERALLOYS. Acta Metall Sin, 1983, 19(3): 30-148.
|
|
|
Abstract One of the chief factors influencing the incipient melting in Hf-bearing DS Ni-base superalloys was found out to be Ni_5Hf-phase. The melting peak at 1135—1160℃ showing Ni_5Hf-phase more than 1.0 v.-% has been determined by DTA on heating. A distinguishable segregation of Ni_5Hf in both ends of the directionally solidified ingots by PD technique was shown, and their sensitivities to incipient melting are quite different consequently, The incipient melting of Ni_5Hf-phase may induce the solution of γ+γ′ eutectic and M_3B_2. It was also obtained that the low-carbon or carbon-free Hf-bearing alloys have stronger tendency to incipient melting, as well as the slow cooling microstructure and the increasing rate of solid solution temperature are sensitive to it. The reduction of rupture strength of the alloys may be caused by the presence of incipient melting of Ni_5Hf more than 3 v.-%. Their rupture is propagated mainly along the interface between the melting zone of Ni_5Hf and the eutectic γ′. By means of pretreatment at 1150℃ for 8h, the Ni_5Hf-phase may be completely eliminated, thus the incipient melting of the Hf-bearing alloys may be effectively brought under control.
|
|
Received: 18 March 1983
|
1 Duhl, D. N.,; Sulivan, C. P., J. Met., 23 (1971) , 38．
2 郑运荣;蔡玉林,未发表工作,1981．
3 Bnrton, C. J., Superalloys: Metallurgy and Manufacture, Proc. 3rd Int. Symp. on Superalloys, Eds. Kear, B. H.; Muzyka, D. R.; Tien, J. K., et al., Claitor's Pub., Baton Rouge, Louisiana, 1976, p. 147．
4 Gell, M.; Duhl, D. N.; Giamei, A. F., Superalloys, 1980, Proc. 4th Int. Symp. on Superalloys, Eds. Tien, J. K.; Wlodek, S. T.; Morrow, H. Ⅲ, et al., ASM Metal Park, Ohio, 1980, p. 205．
5 Davies, R., GPBO 1 508 099, (1978) . |
| No Suggested Reading articles found! |
|
|
Viewed |
|
|
|
Full text
|
|
|
|
|
Abstract
|
|
|
|
|
Cited |
|
|
|
|
| |
Shared |
|
|
|
|
| |
Discussed |
|
|
|
|
