Alloy design and property evaluation of new Ti–Cr–Nb alloys

Titanium and its alloys are extensively used as biomedical implant materials because their good mechanical properties are accompanied by an excellent biocompatibility and corrosion resistance. However, the most widely used Ti alloy for medical implants, Ti–6Al–4V, does not satisfy a major requirements about non-toxicity and low elastic modulus close to that of cortical bone. Therefore, alternative titanium-based biomedical alloys with other alloying elements are currently the subject of intensive study.This work was conducted to develop new as-cast Ti-based alloys with biocompatible elements, i.e. chromium and niobium addition and low elastic modulus. For this purpose six Ti–Cr–Nb alloys were prepared and their properties were evaluated. The obtained results indicated that experimental alloys have α/β microstructure. Among them, alloys Ti70Cr10Nb20, Ti70Cr20Nb10 and Ti60Cr20Nb20 have very low elastic modulus (17–50 GPa), high strength (1580–1700 MPa) and plasticity (75.0–83.5%) as well as an excellent corrosion resistance. According to the obtained results it could be considered that new biomedical alloys with adequate properties for biomedical applications were developed.

► Six as-cast Ti–Cr–Nb alloys for potential biomedical applications.
► The microstructure consisted of β and α phases and needle-like α″ respectively.
► The hardness increases as the size of α-grains crystallized in β-matrix decreases.
► The low values of E-modulus were a result of niobium addition as a β-stabilizer.
► High pitting potential values indicated very good corrosion resistance of alloys.