Video-controlled tensile testing of alumina fibres and rods manufactured by colloidal processing
Tóm tắt
Concentrated suspensions of alumina were prepared from a commercially available raw powder stabilised with a dispersant. These suspensions were then mixed with a fixed amount of binder and milled for different times, resulting in distinct particle size distributions. The stabilised slurries were tape-cast and dried in an oven at constant temperature and humidity. Good aggregate free pastes were generated from this colloidal process. The pastes were then extruded through various sized dies (from 300 μm to 1.6 mm in diameter), to form fibres and rods of different diameters. These were finally sintered in air at different temperatures: 1400°C, 1500°C and 1600°C. The mechanical properties of these single strand alumina fibres, i.e. Young's modulus and tensile strength, were determined using a computer-assisted video extensometer. The effects of powder processing, sample diameter and sintering temperature on the tensile properties were therefore investigated.
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