Shear Strength of Zirconia Agglomerates

This paper describes a novel technique to measure the shear strength of loose agglomerates. Agglomerates were glued using a low viscosity epoxy on to aluminium plates. The strength was measured by using Hounsfield Tensometer and a Force Gauge. The agglomerates studied were commercially available spray-dried zirconia powders TZ-3Y (Tosoh) and HISY-3SD (Daichi Kigenso Kagaku). The shear strength found for loose agglomerates was compared with other methods of strength measurement reported in literature. Single loose agglomerate shear strength was also evaluated from powder bed in an annular shear cell. The shear strength of loose agglomerates obtained experimentally by direct shear was found higher than that from an annular shear cell, but they were of the same order and the differences consistent with differences in pre-shear treatment. The strength of loose agglomerates is strongly dependent on agglomerate size.