Losses of the alloying elements during vacuum induction melting of the binary NiTi alloys were evaluated by visual observation and chemical analysis of the NiTi melted specimens and the scalp formed on the internal surface of the crucible. The results indicated that the major sources of the losses were (a) evaporation of the metals, (b) formation of the NiTi scalp and (c) the sprinkling drops splashed out of the melt due to the exothermic reactions occurring between Ni and Ti to form the NiTi parent phase. Quantitative evaluations were made for the metallic losses by holding the molten alloy for 0.5, 3, 5, 10 and 15 min at around 100℃ above the melting point inside the crucible.Chemical analysis showed that there existed an optimum holding time of 3 min during which the alloying elements were only dropped to a predictable limit. Microstructure, chemical composition, shape memory and mechanical properties of the cast metal ingots were determined to indicate the appropriate achievements with the specified 3 min optimum holding time.
参考文献
| [1] | T Duerig;A Pelton;D Stockel .[J].Materials Science and Engineering,1999,273-275:149. |
| [2] | Z.Q. Li;Q.P. Sun .SupereIastic NiTi Memory Alloy Micro-Tube under Tension -- Nucleation and Propagation of Martensite Band[J].Key engineering materials,2000(2):461-466. |
| [3] | L M Schetky.Advanced Materials'93[M].Elsevier Science Japan,1994:1131. |
| [4] | S. K. Sadrnezhaad;A. R. Selahi .Effect of Mechanical Alloying and Sintering on Ni-Ti Powders[J].Materials and Manufacturing Processes,2004(3):475-486. |
| [5] | S J Kim.The First Pacific Rim Int Conf on Adv Mater Process[C].The Mineral Metals Materials Society USA,1992:59. |
| [6] | S. Badakhshan Raz;S. K. Sadrnezhaad .Effects of VIM frequency on chemical composition, homogeneity and microstructure of NiTi shape memory alloy[J].Materials Science and Technology: MST: A publication of the Institute of Metals,2004(5):593-598. |
| [7] | ASM Metals Handbook.Properties, selection: Nonferrous Alloys[M].Special Purpose Materials ASM International USA,1998 |
| [8] | T W Duering;R A Pelton.Materials Properties Handbook[M].Titanium Handbook ASM International USA,1994 |
| [9] | K Sadrnezhaad;F Mashhadi;R Sharghi .[J].Materials and Manufacturing Processes,1997,12(01):107. |
| [10] | Desk Handbook.Phase Diagram for Binary Alloys[M].ASM International USA,1994 |
| [11] | F M H Zarandi;K Sadrnezhaad .[J].Materials and Manufacturing Processes,1997,12(06):1093. |
| [12] | S Badakhshan Raz.Master Thesis[M].Sharif University of Technology,2001:85. |
| [13] | S Badakhshan Raz;S H Mirabolghasemi;S K Sadrnezhaad.First Conference on Materials,Metal Forming[C].Sharif University of Technology,2002:297. |
| [14] | H C Yi;J J Moor .[J].Scripta Metallurgica et Materialia,1989,22:1889. |
| [15] | H C Yi;J J Moor .[J].Journal of The Minerals,Metals & Materials Society,1989,22:31. |
| [16] | V E Gjunter;P Sysoliatin;T Termerkhamor.Superelastic Shape Memory Implants in Maxillofacial Surgery,Traumatology, Orthopedics, Neurosurgery[M].Tomsk University Publishing Tomsk Russia,1995:14. |
| [17] | B Y Yun;L G Rong;Y Y Li;V E Gjunter .[J].Metallurgical and Materials Transactions,2000,31A:1867. |
| [18] | O Kubachewski;C B Alcok.Metallurgical Thermochemistry[M].Pergamon Press USA,1979 |
| [19] | R L Saha;T K Nandy;R D K Misra;K T Jacob .[J].Metallurgical and Materials Transactions,1990,21B:559. |
| [20] | E R Stover;J Wulff .[J].Transactions Soc AIME,1959,215:127. |
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