Measuring Powder Flow Properties in a Rotating Drum

Influence of Different Powder Conditioning Strategies on Metal Binder Jetting with Ti-6Al-4V

“…However, this method is unsuitable due to the small particle size distribution and the correspondingly poor flow properties. Therefore, a GranuTools Granudrum using the rotating drum method was used [37], which is better-suited to the MBJ process. The principle of this method is illustrated in Figure 2.…”

“…The drum was backlit to enhance contrast for the camera (3), which captured individual images of the powder during the measurement process (see Figure 2). One drawback of the method is the challenge of comparability due to the multitude of different measurable parameters [37]. The dynamic angle of repose 𝛼 and cohesion index (𝐶𝐼) values were selected for this study (see Figure 3).…”

“…The dynamic angle of repose describes the flow angle, as depicted in the left-hand side of the illustration at certain rotating speeds. The cohesion index was determined from the drum diameter used 𝐷 and the fluctuations in the powder surface 𝜎 𝑥 were determined using Formula (1) [37]:…”

“…Both values are strongly dependent on the rotational speed of the drum, which is why they are often specified as a function over a certain range [37]. However, only one sensible speed was selected for the evaluation in the experiments to compare the values more easily.…”

“…However, only one sensible speed was selected for the evaluation in the experiments to compare the values more easily. In this case, 6 rpm was selected and converted into a translational speed of One drawback of the method is the challenge of comparability due to the multitude of different measurable parameters [37]. The dynamic angle of repose α f and cohesion index (CI) values were selected for this study (see Figure 3).…”