Phase transformation and microstructure and mechanical properties of as cast NiTiRe shape memory alloys

Abstract

The microstructure, martensitic transformation and mechanical properties of as cast Ni₅₂Ti_48−xRe_x shape memory alloys (SMAs) were investigated. The microstructure of these alloys consists of B19′ martensite phase as a matrix and B2 austenite in small percentages in addition to some precipitations of NiTi intermetallic compounds. There are two types of NiTi precipitates: the first one is Ti₂Ni, which can be seen in the all microstructures of the three alloys, and the other is Ni₂Ti, which is found only in the microstructure of Ni₅₂Ti_47·7Re_0·3 alloy. According to differential scanning calorimetry measurements, one stage of transformation reaction B2 to B19′ accompanied with forward and backward martensitic transformation was observed. The martensitic peak and the austenitic peak were increased with the addition of rhenium. Both are increased as the number of valence electron per atom increase and the valence electron concentration decrease. Hardness measurements of Ni₅₂Ti_48−xRe_x SMAs are improved by the Re additions.

Keywords

Shape memory alloys Rhenium Microstructure Martensitic transformation NiTi intermetallic compound

Get full access to this article

View all access options for this article.

References

Eckelmeyer

: ‘Titanium nickelide. Structure and properties,’ 1976, Scr. Metall. , 10, 667.

, Wu

and Wayman

: ‘Transformation heat as function of ternary Pd additions in Ti₅₀Ni_50−xPd_x alloys with x: 20–50 at’, Scr. Metall. Mater. , 1990, 24, 1571.

Ibrahim

KhM

, El-Bagoury

and Fouad

: ‘Microstructure and martensitic transformation of cast TiNiSi shape memory alloys’, J. Alloys Compd , 2011, 509, 3913.

Thoma

and Boehm

: ‘Effect of composition on the amount of second phase and transformation temperatures of Ni_xTi_90−xHf₁₀ shape memory alloys’, Mater. Sci. Eng. A , 1999, A273–A275, 385.

Karaca

, Saghaian

, Basaran

, Bigelow

, Noebe

and Chumlyakov

: ‘Compressive response of nickel-rich NiTiHf high-temperature shape memory single crystals along the [1 1 1] orientation’, Acta Mater. , 2009, 57, 3232.

Dalle

, Pasko

, Vermaut

, Kolomytsev

, Ochin

and Portier

: ‘Melt spun ribbons of Ti–Hf–Ni–Re shape memory alloys: first investigations’, Scr. Mater. , 2000, 43, 331.

Kockar

, Karaman

, Kim

and Chumlyakov

: ‘A method to enhance cyclic reversibility of NiTiHf high temperature shape memory alloys’, Scr. Mater. , 2006, 54, 2203.

Balak

and Abbasi

: ‘Influence of the Ti content, training cycles and pre-strain on the two-way shape memory effect in NiTi alloys’, Mater. Des. , 2011, 32, 3992.

Zou

, Han

, Wang

, Zhang

W.-Z

and Lai

JKL

: ‘TEM and HREM study of the interphase interface structure of Ti₃Ni₄ precipitates and parent phase in an aged TiNi shape memory alloy’, Mater. Sci. Eng. A , 1996, A219, 142.

10.

Lai

, Wang

, Zhang

, Yang

: ‘A new precipitate phase in a TiNiHf high temperature shape memory alloy’, Acta Mater. , 1998, 46, 273.

11.

Meng

, Cai

, Chen

and Zhao

: ‘Effect of aging on martensitic transformation and microstructure in Ni-rich TiNiHf shape memory alloy’, Scr. Mater. , 2006, 54, 1599.

12.

Wang

, Zheng

, Cai

and Zhao

: ‘The tensile behavior of Ti₃₆Ni₄₉Hf₁₅ high temperature shape memory alloy’, Scr. Mater. , 1999, 40, 1327.

13.

Meng

, Zheng

, Wang

and Zhao

: ‘Effect of aging on the phase transformation and mechanical behavior of Ti₃₆Ni₄₉Hf₁₅ high temperature shape memory alloy’, Scr. Mater. , 2000, 42, 341.

14.

Dalle

, Perrin

, Vermaut

, Masse

and Portier

: ‘Interface mobility in Ni_49·8Ti_42·2Hf₈ shape memory alloy’, Acta Mater. 2002, 50, 3557.

15.

Morakabati

, Aboutalebi

, Kheirandish

, Karimi

and Abbasi

: ‘Hot tensile properties and microstructural evolution of as cast NiTi and NiTiCu shape memory alloys’, Mater. Des. , 2011, 32, 406.

16.

Zarinejad

, Liu

and Tong

: ‘Transformation temperature changes due to second phase precipitation in NiTi-based shape memory alloys’, Intermetallics , 2009, 17, 914–919.

17.

Feng

, Ping

, Chang

and Qichuan

: ‘Effects of Ni addition on the microstructure and compressive deformation behavior in Zr–Cu–Ni martensitic alloys’, Mater. Des. , 2012, 34, 143.

18.

Jiang

S.-y

and Zhang

Y.-q

: ‘Microstructure evolution and deformation behavior of as-cast NiTi shape memory alloy under compression’, Trans. Nonferr. Met. Soc. China , 2012, 22, 90.

19.

Wang

, Yan

, Xiao

, Marchenkov

, Xu

and Yang

: ‘Effect of electron density on the martensitic transition in Ni–Mn–Sn alloys’, J. Alloys Compd , 2011, 509, 6834.

20.

de Arajo

, da Silva

and Gonzalez

: ‘A comparative study of Ni–Ti and Ni–Ti–Cu shape memory alloy processed by plasma melting and injection molding ‘, Mater. Des. , 2011, 32, 4925.

21.

Yang

, Liu

and Timothy

: ‘The crystal chemistry of martensite in NiTiHf shape memory alloys’, Intermetallics , 2008, 16, 876.

22.

Hsieh

, Wu

and Lin

: ‘Transformation temperatures and second phases in Ti–Ni–Si ternary shape memory alloys with Si≤2 at.’, J. Alloys Compd , 2002, 339, 162.