Microstructural Investigations in Metals Using Atom Probe Tomography with a Novel Specimen-Electrode Geometry

A new atom probe design is presented along with data showing spectral performance and selected microstructural characterization examples. The instrument includes a curved reflectron, a 532-nm laser, and an integrated, fixed-position, counter electrode in a configuration with moderate electric field enhancement that includes improvements in ease of use and cost of ownership. Both voltage-pulsed and laser-pulsed performance is shown for a variety of materials including Al, Si, W, 316 stainless steel, Inconel 718, and GaN. Characterization of grain boundaries and phase boundaries, including correlation with transmission electron backscatter diffraction results in Inconel 718, is shown. A detailed case study of the resultant microstructure between laser-beam and electron-beam additive manufacturing paths in Inconel 718 is also presented.