Influence of Process Parameters on Mechanical and Corrosion Behavior of DED-Processed Biomedical Ti-35Nb-7Zr-5Ta Alloy

The laser-engineered net-shaping (LENSTM) process was employed for directed energy deposition (DED) of Ti-35Nb-7Zr-5Ta (wt.%) or TNZT, a low modulus metastable beta-Ti alloy for biomedical applications. The laser power was varied in the range of 400-600 W, while keeping all other parameters constant. A change in the overall grain morphology was noted in the sample with an increase in the laser power. The higher laser power samples showed more columnar grains compared to the equiaxed grains observed in the 400-W condition. The DED-processed TNZT alloys exhibited a combination of high tensile yield strength (similar to 500 MPa) and ductility (similar to 25%). Moreover, the alloys also exhibited excellent corrosion resistance in Ringer's solution. Overall, the results indicate that the LENS-deposited TNZT alloy could be a promising candidate for biomedical applications.