Harmonic Structured Ti6Al4V by Spark Plasma Sintering

The Ti6Al4V alloy has been applied in situations where mechanical strength, corrosion resistance and biocompatibility are the concern, as in permanent biomedical implants. These material properties are straightly correlated with the microstructure morphology as grain size and crystallographic phases, which is very dependent of the thermal mechanical history and the chemical composition. The Ti6Al4V harmonic structure was primarily achieved by means of Mechanical Ball Milling (MBM) and Spark Plasma Sintering (SPS) using pre-alloyed powder from the plasma rotating electrode processes (PREP). This work aimed at developing the harmonic microstructure by MBM and SPS using pre-alloyed gas atomized powder (GAP). The chemical composition, the microstructure and the hardness were evaluated for the sintered samples and for the commercial wrought annealed conditions, for comparison. The harmonic structure obtained consists of cores containing alpha lath coarse grains surrounded by a three-dimensional network of fine equiaxial grains, while the wrought material shows equiaxial alpha grains in a matrix of beta phase microstructure. The sintered material revealed higher hardness than the wrought alloy.