The authors report on pulsed laser powder bed fusion fabrication of nitinol (NiTi) shape memory materials. The authors first performed single-track laser parameter sweeps to assess melt pool stability and determine energy parameters and hatch spacing for larger builds. The authors then assessed the melt pool chemistry as a function of laser energy density and build plate composition. Brittle intermetallics were found to form at the part/build plate interface for both N200 and Ti-6-4 substrates. The intermetallic formation was reduced by building on a 50Ni-50Ti substrate, but delamination still occurred due to thermal stresses upon cooling. The authors were able to overcome delamination on all substrates and fabricate macroscopic parts by building a lattice support structure, which is both compliant and controls heat transfer into the build plate. This approach will enable scalable fabrication of complex NiTi parts.
|Original language||English (US)|
|Number of pages||7|
|State||Published - 2019|
ASJC Scopus subject areas
- Materials Science(all)