AlO/ZrO Materials as an Environmentally Friendly Solution for Linear Infrastructure Applications.

The present work deals with the evaluation of the effect of ZrO on the structure and selected properties of shapes obtained using the centrifugal slip casting method. The samples were made of alumina and zirconia. The applied technology made it possible to produce tubes with a high density reaching 99-100% after sintering. Very good bonding was obtained at the AlO/ZrO interphase boundaries with no discernible delamination or cracks, which was confirmed by STEM observations. In the case of AlO/ZrO composites containing 5 vol.% and 10 vol.% ZrO, the presence of equiaxial ZrO grains with an average size of 0.25 µm was observed, which are distributed along the grain boundaries of AlO. At the same time, the composites exhibited a very high hardness of 22-23 GPa. Moreover, the environmental influences accompanying the sintering process were quantified. The impacts were determined using the life cycle analysis method, in the phase related to the extraction and processing of raw materials and the process of producing AlO/ZrO composites. The results obtained show that the production of 1 kg of sintered composite results in greenhouse gas emissions of 2.24-2.9 kg CO eq. which is comparable to the amount of emissions accompanying the production of 1 kg of Polyvinyl Chloride (PVC), Polypropylene (PP), or hot-rolled steel products.