Experimental study on the anisotropic behavior of textured NiTi pseudoelastic shape memory alloys

The pre-textured NiTi shape memory alloys (SMAs) are used in the mechanical testing. The pseudoelastic effect and the anisotropic behavior of NiTi SMA are observed. The material behaviors such as hysteresis area in loading-unloading cycle, austenite Young's modulus, martensite transformation stress and the recoverable pseudoelastic transformation strain are analyzed experimentally. The results show that the material behaviors of the textured NiTi SMAs are all closely related to the material's orientation to the rolling direction. The transformation stress and Young's modulus get the maximum values at the same orientation of the cutting direction to the rolling direction. For the recoverable pseudoelastic transformation strain and hysteresis area, they get the maximum values at the same orientation but the angle is different from that for the transformation stress and Young's modulus. It is also suggested that the user control the texture of the material and optimal use the SMAs according to the practical applications. (C) 2003 Elsevier B.V. All rights reserved.