Development of a (partially) automated measuring device for simple, precise and fast determination of the particle size of spherical metal powders

Initial situation and problem definition

The exact characterization of metal powders is essential for the production of high-quality components in industrial process chains. Particle size and particle size distribution significantly influence product properties such as strength or surface quality. In practice, the average particle size of metal powders is usually determined using the pressure loss in densely packed powder samples (Kozeny-Carman equation). This test method is standardized in ASTM standard B330. The current practical measurement standard is based on manual sample preparation and analog determination of measured values. All process steps are subject to a high degree of inaccuracy, and further processing (evaluation) of the data is time-consuming as it can only be carried out manually.

Project objectives

The device to be built should consist of three functional modules. In the first module, the sample must be pressed and the height measured. The process must be carried out precisely with a defined force of 222N on an area of 1,277 cm². A second module is responsible for gas management and pressure loss measurement. The volume flow increase [ml/s²] must remain constant. The maximum inlet pressure upstream of the sample must not exceed 500 mbar. The third module required is a computer unit and a touchscreen. The module manages the basic settings, executes the control program (based on Python), organizes the menu navigation and performs all calculations.

Solution approach

A (partially) automated measuring device is to be developed and tested that enables simple, precise and fast determination of the particle size of metal powders with an average particle size of 0.3 µm to 100 µm. Two prototypes need to be produced and tested to validate the functionality, ergonomics and cost of the measuring device. The second prototype will take into account possible improvements resulting from the practical use of the first prototype. The main objectives are to make the device easy to use and to ensure fast, accurate and cost-effective measurements.