A non-invariant plane model for the interface in CuAlNi single crystal shape memory alloys

A non-invariant plane model for the austenite-martensitic (A-M) interface in CuAlNi single crystal shape memory alloys (SMAs) is proposed in this paper. The model is based on the crystallography of martensitic transformation and the recent uniaxial tensile Moiretests on Cu-14%Al-4.12%Ni (wt%) single crystals. The two types of specimens used have the same tensile axis orientation but have different transition temperatures. One exhibits Shape Memory Effect (SME) and the other exhibits Superelasticity (SE). In the case of SME, the plane invariant nature of the A-M interface is well verified by the Moiretest. On the contrary, the A-M interface in the case of SE was identified to be a non-invariant plane. A crystallography- based model is proposed to explain the formation of this non-plane-invariant A-M interface in SE and is used to predict the resultant interface structure and the transformation strain of the stress-induced b1!b 9 transformation in CuAlNi. The comparison between the theoretical calculations and the experimental results support the proposed model. © 2000 Elsevier Science Ltd. All rights reserved.

[1]  Kaushik Bhattacharya,et al.  Wedge-like microstructure in martensites , 1991 .

[2]  Shou-wen Yu,et al.  On the strain jump in shape memory alloys - A crystallographic-based mechanics analysis , 1999 .

[3]  T. Shield.  Orientation dependence of the pseudoelastic behavior of single crystals of CuAlNi in tension , 1995 .

[4]  P. Ifju,et al.  High Sensitivity Moiré: Experimental Analysis for Mechanics and Materials , 1995 .

[5]  L. C. Brown,et al.  The thermal effect due to stress-induced martensite formation in Β-CuAlNi single crystals , 1980 .

[6]  H. Kato.  Habit plane analysis of the CUBIC/18R(9R) martensite transformation in copper-based shape memory alloys , 1998 .

[7]  K. Bhattacharya.  Self-accommodation in martensite , 1992 .

[8]  Qingping Sun,et al.  On Deformation of A-M Interface in Single Crystal Shape Memory Alloys and Some Related Issues , 1999 .

[9]  Shuichi Miyazaki,et al.  Development of Shape Memory Alloys , 1989 .

[10]  K. Shimizu,et al.  Morphology and Crystallography of Thermoelastic γ' Cu-Al-Ni Martensite , 1969 .

[11]  Shuichi Miyazaki,et al.  Orientation dependence of β1 → β1′ stress-induced martensitic transformation in a Cu-AI-Ni alloy , 1988 .

[12]  K. Shimizu,et al.  Successive stress-induced martensitic transformations and associated transformation pseudoelasticity in Cu-Al-Ni alloys , 1979 .

[13]  P. Tong,et al.  On the Full-Field Deformation of Single Crystal CuAlNi Shape Memory Alloys—Stress-Induced β1 → γ'1 Martensitic Transformation , 1997 .

[14]  J. Ball,et al.  Fine phase mixtures as minimizers of energy , 1987 .

[15]  C. M. Wayman,et al.  Introduction to the crystallography of martensitic transformations , 1964 .

[16]  L. C. Brown,et al.  Stress-induced martensite formation in Cu−Al−Ni alloys , 1971, Metallurgical Transactions.

[17]  K. Shimizu,et al.  Electron Microscopy Study of Stress-induced Acicular γ′ Martensite in Cu–Al–Ni Alloy , 1974 .

[18]  T. Buchheit,et al.  Predicting the orientation-dependent stress-induced transformation and detwinning response of shape memory alloy single crystals , 1996 .

[19]  K. Shimizu,et al.  Crystallography of β1 → γ′1 stress-induced martensitic transformation in a CuAlNi alloy , 1986 .

[20]  Q. Sun,et al.  Some Recent Advances in Experimental Study of Shape Memory Alloys , 1999 .

[21]  大塚 和弘,et al.  Solid - solid phase transformations , 1999 .