A New Kind of Biomedical Ti–Mn–Nb Alloy

Abstract

Titanium and its alloys are widely used as implant biomaterials due to their well mechanical properties and biological compatibilities. Nb and Mn are well‐known alloying elements with biological potential. Herein, the Ti–Mn–Nb phase equilibria at 900 °C (Ti‐rich region) is determined and published. According to the β single‐phase field in this phase diagram (at 900 °C), Ti–xMn–yNb (x = 4, 10, 16; y = 2, 8, 14, at%) alloys are selected and fabricated which are suited for solution heat treatment. The Ti–Mn–Nb alloys are investigated by optical microscopy (OM), X‐ray diffraction (XRD), and mechanical testing. A unique diffraction pattern (interpreted as occurrence of a transition phase) is observed by transmission electron microscopy (TEM) in Ti–10Mn–2Nb. In the in vitro evaluation, the human osteoblasts (MG63) adhere well and proliferate on the surface of Ti–xMn–yNb (x = 4, 10; y = 2, 8, 14, at%). According to cell culture experiments, the alloys are nontoxic to human osteosarcoma cells in comparison with pure titanium. Based on a performed screening study, different titanium alloys Ti–4Mn–yNb (y = 2, 8, 14) appear as the biomaterial with the highest potential around 700 MPa ultimate tensile strength and 9–10% elongation.

X-ray diffraction for phase identification in Ti-based alloys: benefits and limitations

“…The peak with the highest relative intensity is the α-Ti (101) plane in the case of pure Ti (figure 1(a)) and the β-Ti (100) family of planes for stable beta Ti alloys (figure 5(a)). This behaviour is common in literature as exemplified by the work of Niu et al [28] on Ti foils obtained via thermomechanical processing and that of Wang et al [36] on Ti-Mn-Nb alloys produced via arc melting, respectively.…”

“…However, the accuracy, as dictated by the minimum detection limit of the equipment, can lead to misjudgement of the phases present if not complemented with data from other characterisation' techniques, microstructural analysis in this instance. Microscopy techniques relevant to the clarification of the phases present in Ti alloys span from optical microscopy for determining the grain size in single-phase alloys [37], to SEM-EDS to confirm the chemistry and nature of generally μm-size phases [36], to TEM to commonly characterise nm-size features [38]. The need of complementing data for such verification constitutes a limitation of the XRD technique.…”

“…Contrarywise, only diffraction peaks of the β-Ti phase were found for the Ti-10Mn alloy. Coherently, Wang et al [36] found a comparable behaviour where the microstructure is composed of equiaxed β-Ti grains and only β-Ti phase XRD peaks are detected in their proposed new biomedical Ti-Mn-Nb alloys subjected to a solution treatment.…”