Synthesis and characterization of mechanically alloyed nanostructured ternary titanium based alloy for bio-medical applications

This research article interprets the findings of experimental investigation on synthesis and characterization of a Ti alloy powder by using a high-energetic ball milling (HEBM) process. The work focuses on the synthesis of alloy powder with 70:10:20 (atomic %) of Ti, Mg, and Sr powders by process of mechanical alloying thereby decreasing the grain size of the particles to a Nanoscale regime from a micron scale. Tungsten carbide milling media was selected to synthesize alloy due to its higher density compared to elemental powder mixtures. Furthermore, the production of ternary Ti alloy with Mg and Sr additions could enhance the structural properties with density reduction which are quite suitable for biomedical applications. Mechanically alloyed powders are then characterized by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) with EDS, and High-Resolution Transmission electron microscopy (TEM) to investigate the structural, phase transformation, compositional, morphology, and topography. XRD results revealed that the crystallite size decreased to 32.07 nm, and the formation of nonequilibrium intermetallic phases such as MgTiO₃, Mg₂₃Sr₆, Mg₂Sr, and Sr₃Ti₂O₇, with an increase in ball-milling duration. However, the absence of sharp peaks indicates partial amorphization of crystalline powders as the milling progresses. SEM analysis at 30 hr of milling time, the powder particles fractures, disintegrate to finer size and agglomerates by the process of welding. TEM revealed nano crystallites and amorphous structures, whereas the selected area diffraction pattern shows a halo amorphous image as well as crystalline brilliant rings, indicating a shift from crystalline to the partial amorphous structure during the ball milling process. The developed novel Ti-Mg-Sr alloy (wherein, Titanium for longer life span, Sr and Mg improve mineral density and bone strength) could be useful for biomedical application.