Ingredient Losses during Melting Binary Ni-Ti Shape Memory Alloys

J Mater Sci Technol ›› 2005, Vol. 21 ›› Issue (04): 484-488.

• Research Articles • Previous Articles Next Articles

Ingredient Losses during Melting Binary Ni-Ti Shape Memory Alloys

S.K.Sadrnezhaad, S.Badakhshan Raz

Center of Excellence for Advanced Processes of Production and Shaping of Materials, Department of Materials Science and Engineering, Sharif University of Technology, Tehran, P.O. Box 11365-9466, Iran

Received:2004-06-09 Revised:2004-11-01 Online:2005-07-28 Published:2009-10-10
Contact: S.K.Sadrnezhaad

Abstract

Abstract: 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.

Key words: Shape memory alloy (SMA), Vacuum induction melting (VIM), Metallic loss

S.K.Sadrnezhaad, S.Badakhshan Raz. Ingredient Losses during Melting Binary Ni-Ti Shape Memory Alloys[J]. J Mater Sci Technol, 2005, 21(04): 484-488.

References

[1] T.Duerig, A.Pelton and D.Stockel: Mater. Sci. Eug., 1999, 273-275, 149.
[2] Z.Q.Li and Q.P.Sun: Key Eng. Mater., 2000, 177-180, 461.
[3] L.M.Schetky: Advanced Materials'93, Elsevier Science, Japan, 1994, 1131.
[4] S.K.Sadrnezhaad and A.R.Selahi: Mater. Manu. Processes, 2004, 19(3), 475.
[5] S.J.Kim: The First Pacific Rim Int. Conf. on Adv. Mater. Process., The Mineral, Metals and Materials Society, USA, 1992, 59.
[6] S.Badakhshan Raz and S.K.Sadrnezhaad: Mater. Sci. Tecnnol, 2004, 20(5), 593.
[7] ASM Metals Handbook: Properties and selection: Nonferrous Alloys and Special Purpose Materials, ASM International, USA, 1998.
[8] T.W.Duering and R.A.Pelton: Materials Properties Handbook, Titanium Handbook, ASM International, USA, 1994.
[9]K.Sadrnezhaad, F.Mashhadi and R.Sharghi: Mater. Manu. Processes, 1997, 12(1), 107.
[10]Desk Handbook, Phase Diagram for Binary Alloys, ASM, International, USA, 1994.
[11]F.M.H.Zarandi and K.Sadrnezhaad: Mater. Manu. Processes, 1997, 12(6), 1093.
[12]S.Badakhshan Raz: Master Thesis, Sharif University of Technology, 2001, 85.
[13]S.Badakhshan Raz, S.H.Mirabolghasemi and S.K.Sadrnezhaad: First Conference on Materials and Metal Forming, Sharif University of Technology, 2002, 297.
[14]H.C.Yi and J.J.Moor: Scripta Metall, 1989, 22, 1889.
[15]H.C.Yi and J.J.Moor: JOM, 1989, 22, 31.
[16]V.E.Gjunter, P.Sysoliatin and T.Termerkhamor: Superelastic Shape Memory Implants in Maxillofacial Surgery, Traumatology, Orthopedics and Neurosurgery, Tomsk University Publishing, Tomsk, Russia, 1995, 14.
[17]B.Y.Yun, L.G.Rong, Y.Y.Li and V.E.Gjunter: Metall. Mater. Trans., 2000, 31A, 1867.
[18]O.Kubachewski and C.B.Alcok: Metallurgical Thermochemistry, Pergamon Press, USA, 1979.
[19]R.L.Saha, T.K.Nandy, R.D.K.Misra and K.T.Jacob: Metall Trans., 1990, 21B, 559.
[20]E.R.Stover and J.Wulff: Trans. Soc. AIME, 1959, 215, 127.

Ingredient Losses during Melting Binary Ni-Ti Shape Memory Alloys

RichHTML

PDF (PC)

Knowledge

Abstract

Cite this article

share this article

References

Related Articles 1

Recommended Articles

Metrics

Comments