High absorptivity nanotextured powders for additive manufacturing

The widespread application of metal additive manufacturing (AM) is limited by the ability to control the complex interactions between the energy source and the feedstock material. Here we develop a generalizable process to introduce nanoscale grooves to the surface of metal powders which increases the powder absorptivity by up to 70% during laser powder bed fusion. Absorptivity enhancements in copper, copper-silver, and tungsten enables energy efficient manufacturing, with printing of pure copper at relative densities up to 92% using laser energy densities as low as 82 J/mm3. Simulations show the enhanced powder absorptivity results from plasmon-enabled light concentration in nanoscale grooves combined with multiple scattering events. The approach taken here demonstrates a general method to enhance the absorptivity and printability of reflective and refractory metal powders by changing the surface morphology of the feedstock without altering its composition., PowdersTwo copper powders were used in the study. A commercially available copper powder was purchased from LPW/Carpenter Additive (99.95% purity). A second set of copper powder was obtained from Lawrence Livermore National Laboratories (LLNL) (99.99% purity). This powder was made at LLNL through gas atomization using C10100 powder stock. Eutectic AgCu was purchased from LPW/Carpenter Additive (28.1 w% Cu 71.9 w% Ag). Pure W powder with a mean diameter of 45 µm was purchased from Tekna.
Etching PowdersTo etch the Cu and AgCu powders, a solution of FeCl3, HCl, and ethanol at a ratio of ~70g:50ml:150ml was prepared. For 100 g of smooth, as-purchased copper powder, 25 ml of acetic acid was added to a 250 ml Erlenmeyer flask and the native copper oxide layer on the powder was etched for 5 min, during which the solution turned blue due to the dissolution of the copper oxide layer; stirred at 400 RPM using a magnetic stir bar for 4 min and allowed the powder to sediment for 1 min. The acetic ..., , # High Absorptivity Nanotextured Powders for Additive Manufacturing

[https://doi.org/10.5061/dryad.3j9kd51td](https://doi.org/10.5061/dryad.3j9kd51td)

Open Source datasets for the manuscript titled \"High Absorptivity Nanotextured Powders for Additive Manufacturing\".

This dataset contains all the raw data for analysis conducted in the paper. It contains raw data from calorimetry experiments (Calorimetry.zip), nanoindentation experiments (nanoindentation.zip), and both lab-scale X-ray tomography results (all files titled \"Tomography*\").

## Description of the data and file structure

#### Calorimetry

Calorimetry.zip contains CSV files from calorimetry experiments. All calorimetry data was collected using a home-built setup using a National Instruments DAQ and was converted from LVM to CSV. See Methods for additional detail on data collection. Data contains files with titles formatted as follows:

Copper powder naming format:
manufacturer_controlOrEtchedPowder_etchingConcentration_etch...