Stress-induced martensitic transformation in a Ti₄₅Zr₃₈Al₁₇ cast rod

An ordered B2 intermetallic compound with composition Ti₄₅Zr₃₈Al₁₇ was prepared by copper mold casting. The density of the alloy is 5.078 g/cm³, whereas the Poisson's ratio and the Young's modulus are 0.38 and 70 GPa, respectively. Room temperature compression tests show good mechanical properties, namely, a high strength of 1650 MPa combined with a plastic strain of about 19.5 %. These parameters make the material an interesting candidate for biomedical applications like prostheses. Structure investigations reveal that during compression the alloy undergoes a martensitic transformation which proceeds from the parent B2 structure to the orthorhombic B19 structure through an intermediate step involving a hexagonal phase.