Microstructural evolution and corrosion-biocompatibility performance of selective laser melted Ti–10Cu/ZrO2

The present study fabricated Ti–10Cu alloys with and without the addition of 1 wt. % ZrO2 using selective laser melting , with and without subsequent laser remelting. The resulting samples were designated T2 (Ti–10Cu), T4 (Ti–10Cu with remelting), C2 (Ti–10Cu/ZrO2), and C4(Ti–10Cu/ZrO2 with remelting). The aim was to examine how ZrO2 addition and the remelting process affect the microstructure, corrosion resistance, and cytocompatibility of these materials for use in biomedical implants. x-ray diffraction confirmed α/α′ martensitic and Ti2Cu intermetallic phases in all samples. Field emission scanning electron microscopy and electron backscatter diffraction analyses revealed that ZrO2 addition refined the prior β grain size to about 24 μm via heterogeneous nucleation and Zener pinning, while remelting alone caused grain coarsening. The combined effect of ZrO2 and remelting (C4) produced abnormal grain growth with a bimodal microstructure and the strongest crystallographic texture (max m.r.d. 16.86). Electrochemical testing in simulated body fluid revealed that C4 exhibited outstanding corrosion resistance, with a total impedance of 5620 kΩ cm2, approximately 30 times higher than that of T2 and 4.8 times higher than that of Ti–6Al–4V. MTT assays demonstrated that C4 achieved 91.6% cell viability, approaching titanium (94%), attributed to the ZrO2-modified passive film suppressing copper-ion release to subtoxic levels.