Evaluation of powder tensile strength by compression, shear and fluidization modules of the powder rheometer

The properties of powder bed have always been an important research field of powder engineering. In this paper, with the help of FT4 powder rheometer, eight kinds of powder samples from different fields were used as experimental materials, and the bed tensile strengths of the powder were obtained by compression test, shear test and fluidization test. Although the physical properties of the eight materials are different, the three units show the same result trend. Taking the glass bead which meets the hypothesis of the Rumpf equation best as the object, its theoretical tensile strength was calculated. Later, tensile strengths of the glass bead obtained from three experimental methods were compared to its theoretical value to evaluate the accuracy of each test methods. Finally, based on a combination of advantages of the compression test and the fluidization test, a fitting equation was established, providing a simple and time-saving method to obtain the tensile strength of the bed accurately.