New inexpensive Ti‒Mn‒Fe alloys for medical applications

The paper presents the criteria for the design, production and characterization of new low-cost Ti‒Mn and Ti‒Fe alloys, intended for the manufacture of biomedical devices. To obtain these low-cost alloys, a commercial alloy Ti‒6Al‒4V is used, resulting from mechanical processing, to which alloying elements considered biocompatible, such as Fe and Mn, are added. The addition of Mn and Fe aims at stabilizing the β phase of Ti and microstructural refinement, with the aim of improving mechanical performance, while maintaining a low elastic modulus, close to that of human bone. The alloys are obtained by vacuum arc melting under argon protection. Mn and Fe are added in the form of granules with a purity of 99.5%, obtaining the Ti‒3Mn alloy, with a low Fe content, and Ti‒5Fe, with a low Mn content. After melting together, using high purity raw materials (over 99.5%), the concentrations of highly toxic alloying elements, such as V and Al, are reduced. The chemical concentrations of the obtained alloys are determined by X-ray spectrometric analysis, and the examination of the obtained microstructures is performed by optical and scanning electron microscopy. It is found that the Ti‒Mn and Ti‒Fe alloys exhibit homogeneous lamellar microstructures of α + β phases and an improved hardness compared to commercial pure titanium or Ti‒6Al‒4V-type alloys. Such properties indicate a strong potential for their use in the fabrication of biomedical components, particularly orthopaedic and dental implants