Design and Characterization of New Ti-Nb-Hf Alloys

作者：Gonzalez M^*; Pena J; Manero J M; Arciniegas M; Gil F J

来源：Journal of Materials Engineering and Performance, 2009, 18(5-6): 490-495.

DOI：10.1007/s11665-009-9381-2

• low elastic modulus
• nanoindentation
• Ni-free Ti alloys
• shape memory effect

Three new Ni-free Ti alloys Ti-16.2Hf-24.8Nb-1Zr, Ti-5.2Hf-31.2Nb-0.4Zr, and Ti-16Hf-36.2Nb-1Zr (wt.%), were designed and produced in order to obtain shape memory and/or low elastic modulus materials for the use in the load transfer implant field. For that, a method based on the molecular orbital theory was implemented to design the three new Ti-Nb-Hf system alloys. A vacuum arc-melted button of each alloy was treated at 1100 A degrees C for 1.5 h and quenched in a mixture of ethanol/water at 0 A degrees C. Finally, the alloys were microstructurally and mechanically characterized. Special attention on studying the elastic modulus and the thermoelastic martensitic transformation was given by means of nanoindentation tests using a Berkovich and a spherical tip, respectively. X-ray diffraction results showed the presence of beta-phase in the three studied alloys. Moreover, one of the alloys exhibited reversible phase transformation due to the presence of thermoelastic martensitic alpha''-plates inside the beta-grains observed by transmission electron microscopy. Results showed a low elastic modulus in all the studied alloys with values between 70 and 90 GPa, which are lower than those of the commercial alloys used in load transfer bone implants.

• 出版日期2009-8