Corrosion and Tribocorrosion Behaviour of a Ti15Zr15Mo Alloy: Preliminary Insights Into the Effects of Heat Treatment

ABSTRACT The growing demand for titanium alloys with low elastic modulus for bone‐integrated implants has driven the development of novel β‐type alloys. This study examines the corrosion and tribocorrosion behaviours of a Ti15Zr15Mo alloy produced by arc melting, with and without heat treatment at 600°C for 6 h, benchmarked against Ti6Al4V. Corrosion behaviour was evaluated in phosphate‐buffered saline (PBS) at 37°C using potentiodynamic polarisation and electrochemical impedance spectroscopy (EIS). Tribocorrosion tests were performed under reciprocating sliding against a 10 mm alumina ball (1 N, 1 Hz, 600 μm) in PBS, with simultaneous monitoring of open‐circuit potential (OCP) and coefficient of friction (COF). x‐Ray diffraction (XRD) showed a predominance of β phase in the Ti15Zr15Mo alloys, while Ti6Al4V exhibited a dual‐phase structure, with the as‐cast and heat‐treated Ti15Zr15Mo alloys exhibiting microhardnesses of 399 ± 2 HV 0.25 and 433 ± 3 HV 0.25 , respectively, compared to 337 ± 5 HV 0.25 for the Ti6Al4V benchmark. When benchmarked against Ti6Al4V, the Ti15Zr15Mo alloys exhibited lower passive film resistance ( R ox of 0.74 ± 0.05 MΩ cm 2 for as‐cast and 0.60 ± 0.02 MΩ cm 2 for heat treated versus 1.36 ± 0.68 MΩ cm 2 for Ti6Al4V), with heat treatment slightly further impairing the passive layer stability. Furthermore, significantly higher wear volume losses of (4.58 ± 0.46) × 10 −3 and (4.42 ± 1.44) × 10 −3 mm 3 were observed for the as‐cast and heat‐treated Ti15Zr15Mo alloys, respectively, relative to (1.41 ± 0.28) × 10 −3 mm 3 for the Ti6Al4V reference, highlighting the interplay between mechanical properties and tribocorrosion mechanisms.