Three-dimensional particle size, shape, and internal porosity characterization: Application to five similar titanium alloy (Ti-6Al-4V) powders and comparison to two-dimensional measurements

Published

May 26, 2021

Author(s)

Edward Garboczi, Rainer Hebert, Yu Sun, Mark Aindow

Abstract

In an earlier paper, titanium alloy (Ti-6Al-4V) powders from six different vendors were characterized with a number of methods in an attempt to distinguish these powders that were all nominally meeting additive manufacturing standards. One of the methods, two-dimensional (2D) dynamic image analysis (DIA), was used to measure particle size and shape distribution in terms of various parameters. In this present work, samples of five of these same powders were characterized in three dimensions (3D) using a combination of X-ray computed tomography (XCT) and mathematical analysis, with various size and shape parameters, including porosity, measured and calculated for each particle. This 3D characterization was used to mathematically generate 2D projection data, with particles oriented in various ways, so that comparisons could be easily made to the previous DIA measurements. The 3D characterization is used to clearly see differences between the powders, including internal porosity and the percentage of single near-spherical particles (SnS) and non- spherical (NS) particles (mostly multi-particles). Measured 3D XCT-measured parameters are compared to 2D DIA-measured parameters. In addition, the oriented 2D data generated from the 3D data is used to show that the DIA instrument used gave a partial particle orientation to the particles, which is apparent only in the particle shape data, not in the particle size data, with size being defined in several ways. All these results show that current powder standards, which all five powders met, are inadequate to completely characterize powder size and shape parameters that could be important in a metal additive manufacturing process.

Citation

Additive Manufacturing

Volume

44

Pub Type

Journals

Download Paper

DOI Link

Keywords

Ti64, metal powder, X-ray computed tomography, additive manufacturing, particle size, particle shape, dynamic image analysis

Citation

Garboczi, E. , Hebert, R. , Sun, Y. and Aindow, M. (2021), Three-dimensional particle size, shape, and internal porosity characterization: Application to five similar titanium alloy (Ti-6Al-4V) powders and comparison to two-dimensional measurements, Additive Manufacturing, [online], https://doi.org/10.1016/j.addma.2021.102060 (Accessed May 3, 2024)