Abstract Scope |
A brief overview will be given for 3D printing of Ti-6Al-4V. Adaptation of printing parameters in both electron beam and laser powder bed to non-standard powders has been demonstrated, including the use of strongly non-spherical particles as, e.g., in HDH powder. The underlying approach is to identify a process window i.e., interdependent parameter ranges in power, speed, hatch etc. that result in >99% density. Lack-of-fusion provides one limit based on melt pool overlap. Synchrotron-based high speed imaging has revealed the prevalence of keyholes and quantified their extent including, crucially, the boundary for keyhole porosity formation. Microstructures vary between martensitic and basketweave; here again, high speed synchrotron diffraction experiments help to quantify many details. Laser hot wire deposition with millimeter-scale tracks produces banded microstructures that arise from locally long dwell at the transus and consequent variations in properties, all of which can be modeled. Textures are columnar and therefore anisotropic. |