Effect of Mo and space holder content on microstructure, mechanical and corrosion properties in Ti6AlxMo based alloy for bone implant

摘要

The porous alloys of Ti6Al(3-15)Mo were developed to replace the fractured bone; the alloy consists of 6 wt% of Al which was taken as alpha the phase stabilizer and (3-15) wt% Mo with an increment of 3 wt% was taken as beta phase stabilizer. The porosity of these fabricated porous alloys was controlled by adjusting volume% of the ammonium bicarbonate (SH). These porous samples were characterized in terms of their microstructure, compressive strength, elastic modulus, energy absorption, ion release and corrosion rate in simulated body fluid (SBF) and these properties are compared with the existing alloys and human bone. The fabricated porous samples were characterized, and the obtained results were analysed as a function of Mo concentration and the volume% of space holder content. Three phases were found in the microstructure: alpha, alpha(2) and beta phase of titanium. Increase in Mo content from 3 to 15 wt% has increased the volume fraction of beta phase from 7.45% to 64.09% and Kirkendall pores also are observed to be increased with increase in Mo content. alpha and alpha(2) phase was differentiated by the TEM and phase map of EBSD images. The plateau stress, elastic modulus and energy absorption are observed to be decreased, and the densification strain is observed to be increased with the addition of Mo and SH content. The released ion concentration and corrosion rate are far below the tolerance limits of Ti, Al and Mo elements, in the static immersion test conducted in SBF solution.