Main goal of modern biocompatible metallic materials development is, by all means, functioning of surgically implanted medical implants without any damage and without any need for revising surgery. Namely, medical implants lifespan prolongation and patients' life quality improvement is of prime concern in modern age. Production of durable artificial hip, shoulder and knee joints requires understanding of complex interactions between metallic biomaterials, operating conditions and material damage because implanted biometallic materials are subjected to mechanical loading in corrosive environment, such are body fluids, which consequently lead to material degradation and premature implant failure. Establishing complex dependence between implant material chemical composition, microstructural characteristics and thermo-mechanical processing parameters throughout extensive examinations and numerical modeling of material properties and damage mechanisms is essential for understanding of implant material behavior in simulated body conditions. Having all that in mind the purpose of the present multidisciplinary study was to examine damage and fracture resistance of (α+β)- and β-type implant titanium alloys subjected to physiological solution and stress present in the human body and artificial joints during the walking cycle. An insight into corrosion resistance, tribolological behavior, mechanical properties and damage mechanics of commercial implant Ti-6A1-4V ELI (Extra Low Interstitial) (mass %) alloy and new generation Ti-13Nb-13Zr (mass %) alloy was established as dependent on alloy microstructural characteristics and tribo-corrosive environment conditions. Finite element method (FEM) and micromechanical models were applied for investigated alloys fracture toughness prediction and numerical analysis of their fracture resistance. Diverse microstructural morphologies of investigated alloys were obtained by careful selection of conventional thermal/thermo-mechanical processing parameters or by applying modern high pressure torsion (HPT) processing procedure for nanocrystalline material production. Alloy microstructural characterization was conducted using optical microscopy (OM), scanning electron microscopy (SEM) and X-ray diffraction (XRD). Geometrical microstructural parameters of conventionally produced alloys were determined using image analysis technique. Influence of alloy microstructural features on alloys wear and friction resistance in conditions which mimic in vivo conditions was examined at macro and micro level under diverse normal loads and sliding speeds. Evaluation of alloys tribological behavior resulted in determination of frictional and wear properties, wear mechanism, as well as in characterization of contact zone modifications. For wear products and mechanism identification post test examination of worn surfaces was carried out using SEM and XRD. Corrosion behavior of investigated alloys was examined in aerated Ringer's solution by potentiodynamic method and electrochemical impedance spectroscopy (EIS). Corrosion properties, such as electrochemical parameters and surface oxide layers characteristics, were determined at room (25°C) or body temperature (37°C). Mechanical properties of investigated alloys under static, impact or dynamic loading at room temperature were investigated. Alloy hardness, tensile properties, impact toughness, as well as fracture mechanics characteristics (critical values of stress intensity factor, KIc, crack tip opening displacement, CTODt, and crack mouth opening displacement, CMODi) and fatigue crack grow resistance (fatigue crack grow rate, da/dN, and fatigue threshold, ΔKth), were obtained as results of these investigations. Digital stereometry was used in order to determine true stress and true strain distribution during tensile and fracture mechanics testing. Crack growth resistance curve (CTOD-Δa) was obtained by applying the modified normalization method. Influence of alloy chemical composition and microstructural features on alloy fracture mechanisms was additionally examined using SEM fractographic analysis. Influence of titanium alloys microstructural parameters on alloy fracture mechanics characteristics was determined using FEM and micromechanical modeling. Ductile fracture initiation and propagation in conventionally processed alloys were simulated by applying complete Gurson model (CGM) and using FEM method incorporated into ABAQUS software application, while micromechanical models of Hahn and Rosenfield, Krafft and Broberg were used for fracture toughness modeling and KIc prediction. Macro tribological examinations revealed that solution treated Ti-6A1-4V ELI alloy shows higher wear resistance then thermo-mechanically processed Ti-13Nb-13Zr alloy, regardless of its microstructural morphology. At all investigated conditions Ti-6A1-4V ELI alloy solution treated in the β phase field exhibits the highest wear resistance, while the highest wear loss was registered for the microstructure formed during rapid cooling from the (α+β) field. Wear behavior of investigated alloy in different microstructural conditions is governed by different dominant wear mechanism, i.e. presence of corrosive wear, abrasive wear, adhesive wear or material transfer mechanism in overall wear damage mechanism. Results of presented investigations revealed that wear rate of investigated alloys is inversely proportional to the alloy hardness and, as a result, higher material transfer from contact surface of Ti-6A1-4V ELI alloy with equiaxed/globular microstructure, as well as from cold-rolled Ti-13Nb-13Zr alloy with martensitic morphology, caused better frictional properties. Alloy microstructural morphology, presence of Ringer's solution and artificial joint material show great influence on titanium alloys frictional properties at micro level. Under all investigated conditions the best frictional properties in contact with AI2O3 exhibits Ti-6A1-4V ELI alloy with equiaxed morphology, while Ti-6A1-4V ELI alloy with martensitic microstructure is characterized with the worst micro tribological properties among all investigated materials. Results of corrosion tests revealed that corrosion resistance of titanium alloys is highly dependent on alloy thermal and thermo-mechanical processing. Since higher solution treatment temperature results in the lower corrosion resistance of Ti-6A1-4V ELI alloy, higher alloy corrosion resistance in Ringer's solution after solution treatment in the (α+β) field was observed. On the other hand, Ti-13Nb-13Zr alloy is characterized with the lower corrosion resistance and exhibits somewhat better corrosion properties in cold-rolled than in hot-rolled condition. However, incompact oxide layers formed at the Ti-13Nb-13Zr alloy surface could influence the alloy osteointegration improvement and maintenance of alloy corrosion resistance properties in spite of possible mechanically induced surface damage. Effect of microstructural morphology on mechanical properties of titanium alloys is quite extensive. Obtained results revealed that Ti-6A1-4V ELI alloy shows higher yield and tensile strength than Ti-13Nb-13Zr alloy, regardless of alloy microstructural characteristics, while its Young's modulus is 4-10 times higher than that of human bone. On the other side, Ti-13Nb-13Zr alloy with martensitic microstructure shows more appropriate biocompatible characteristics due to its quite satisfactory tensile strength values combined with the lowest Young' modulus value. Application of HPT method for the Ti-6A1-4V ELI alloy processing can significantly improve alloy biomechanical compatibility and make it concurrent with Ti-13Nb-13Zr alloy. Morphological features of investigated alloys also show significant influence on their properties when subjected to dynamic loading. Namely, based on research results it can be concluded that the lower solution treatment temperature and the formation of the two-phase (α+β) equiaxed/globular microstructure lead to higher impact toughness, as well as lower crack initiation and propagation resistance of investigated alloys. Also, results confirmed that the fatigue crack propagation rate is higher as microstructural morphology of Ti-6A1-4V ELI alloy shifts from equiaxed/globular to acicular. The highest fatigue limit is observed for alloy with globular microstructure, while alloy with martensitic microstructural features shows the lowest fatigue limit. On the other hand, results of Ti-6A1-4V ELI alloy fracture toughness testing confirmed higher resistance to crack initiation and propagation of alloy with acicular morphology than in the case of alloy solution treated in the (α+β) field. Among all investigated Ti-6A1-4V ELI alloy morphologies the lowest fracture toughness value was obtained for the equiaxed microstructure, while the highest value was obtained for the lamellar morphology. Fracture toughness of Ti-13Nb-13Zr alloy is significantly lower and examination of hot-rolled alloy indicated brittle behavior under investigated conditions. Numerical simulation and analysis of ductile fracture initiation and propagation with CGM model, as well as investigated alloys fracture toughness prediction by applying micromechanical modeling, resulted in quite satisfying matching of experimental and numerical data. Fracture initiation and propagation in globular Ti-6A1-4V ELI and martensitic Ti-13Nb-13Zr alloy subjected to mechanical loading was successfully predicted using local approach to fracture. Significant variations of numerically obtained data are avoided by applying 3D model and finite element of suitable size. Local approach to fracture, which takes into account the presence of brittle fracture in overall fracture mechanism, is used for reliable prediction of titanium alloys fracture behavior. Modified micromechanical models, which incorporate relevant microstructural parameters, are successfully used for Kic estimation and prediction. Funkcionisanje