Simplifying Elemental Characterization of Additive Manufacturing Materials with an Innovative Solution

This presentation describes an innovative solution for characterizing additive manufacturing feedstock powders, wires, and metal printed parts. Currently, full elemental characterization of these materials requires multiple analytical techniques. Inductively Coupled Plasma Mass Spectrometry or Atomic Emission Spectrometry can measure the material’s metallic and residual constituents, however, these methods involve complicated sample preparation procedures, signal interference corrections, and calibration. These are both time consuming and require a highly trained analytical chemist to execute properly. Additionally, these methods fail to measure low-mass elements (i.e., elements with atomic numbers lower than 11). Therefore, additional methods such as inert gas fusion and combustion are needed to quantify low-mass elements (e.g., carbon, nitrogen, oxygen).

An innovative technology, Laser Ablation Laser Ionization Time Of Flight Mass Spectrometry (LALI-TOF-MS), addresses many of the challenges associated with other analytical techniques by combining trace-level detection capabilities for virtually the entire periodic table with intuitive, efficient operations. It uses two lasers to first liberate material from the sample’s surface via ablation, and then ionize that liberated material in a second, laser-ionization step. Analyzing solid samples directly eliminates the complicated sample preparation procedures required by other techniques that rely on liquid sample introduction. After ionization, particles move through the optics system to the TOF mass analyzer, which measures the time required for ions of different masses to traverse the flight tube and impact a detector. This generates a full mass spectrum for each laser shot, facilitating multielement quantification.

Additive manufacturing materials developers have tested the capabilities of LALI-TOF-MS on a variety of metal materials. Finished parts and feedstock wires can be analyzed directly while feedstock powders require pelletization with a standard pellet die set and press. Quantification is performed using the average mass spectra from triplicate raster areas of thousands of mass spectra each.