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A complete study of Ms-30°C polycrystalline CuAlBe shape memory alloy is made by X Ray diffraction using a texture goniometer equipped with a curved position sensitive detector. Austenite and martensite unit cells parameters are measured. Measured indexes and orientation of the habit plane are compared to those expected by the lattice parameters. Austenite after extrusion shows a strong fiber texture, volumic fraction of austenite and martensite are measured according to the deformation. Internal deformations of three grains of a Ms-100°C CuALBe sample are followed during their macroscopic deformation.

X-ray diffraction experiments were carried out to prove that X-ray methods can be used to assess strain-induced fatigue in CuAlBe shape-memory alloys. The pseudoelastic fatigue behaviour of CuAlBe single crystals presents a strong decrease of the critical stress of the martensitic transformation. During the fatigue test, the austenitic lattice exhibits a lattice distortion. This lattice distortion evolves during the fatigue test: the austenitic cubic lattice ( 1 ) tends to transform gradually towards an orthorhombic one. Various hypotheses concerning this lattice distortion are proposed.

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