Characterisation Facilities

This device has been developed for indentation of particles of size down to about 10 micron. It has been equipped with a video microscope for accurate positioning of the indenter, and is completely computer controlled. Measurements of particle hardness and toughness can be performed with this.

This machine, a further development of what used to be a nano-crusher, can be used for wear tests. A particle is subjected to a shearing force induced by rotation of the platform onto which it is mounted.

This device is used for measurement of bulk and side crushing strength of materials. Single granules can be compressed individually between two rigid platens using the Instron 5566 mechanical testing machine with a 10N or 10kN load cell. Punch crosshead speeds (CHS) of 0.01- 500 mmmin -1 . The on-line load-displacement data can be recorded by the system’s computer. The acquired data is used for drawing the load displacement curves. In the confined bulk compression tests, the same mechanical testing machine was employed but the sample is placed in a die.

In this device, single particles are subjected to an impact on a rigid target at a known velocity. This enables correlation of the impact attrition with the single particle properties, such as hardness, toughness, density and size, and also elucidates the effects of different manufacturing processes on particle strength. Using high-speed imaging techniques, we can establish the mechanism (e.g. ductile, semi-ductile or brittle) by which particles break, which is essential for the modelling of particle breakage.

Dietmar Schulze Shear Cell. This device is capable of testing as little as 12 g of powders. The main part of Schulze RTS-XS ® Shear Tester is an annular cell, where the powder specimen is placed. A series of vanes on the bottom of the cell and on the lid prevent powder slipping against the cell boundaries during shearing. The lid is subjected to a vertically acting normal force in order to attain the desired compression level. The normal load is applied by a loading system, which also contains a displacement transducer to measure the lid displacement during shearing in order to capture volumetric changes occurring in the assembly. The shear stress acting on the assembly is continuously monitored by two additional load beams connected to the lid of the annular cell.