The work presents results of research on the influence of micro materials on the thermal conductivity λ of gypsum. In the research, cellulose-based polymer and aerogel were used as the modifying micro materials. For the purpose of measuring the thermal conductivity, a non-stationary method was used based on the “hot wire method”. A very precise set of devices for measuring and recording the temperature of the heating wire was used. In the presented solution, a single measurement took only one minute. Measurements were recorded with the help of a computer measuring system, with a sampling time of 0.01s. During the 60-second-long test, 6000 measurements of the heating wire temperature were collected. A decrease of the thermal conductivity and density of hardened gypsum with added micro materials was observed due to modifications of the structure of the final product. Experimental values of the thermal conductivity of the gypsum specimens with the addition of polymer and aerogel were respectively over 23% and 6% lower than the non-modified gypsum specimen.
The results are based on two experimental high-manganese X98MnAlSiNbTi24-11 and X105MnAlSi24-11 steels subjected to thermo-mechanical treatment by hot-rolling on a semi-industrial processing line. The paper presents the results of diffraction and structural studies using scanning and transmission electron microscopy showing the role of Nb and Ti micro-additives in shaping high strength properties of high-manganese austenitic-ferritic steels with complex carbides. The performed investigations of two experimental steels allow to explain how the change cooling conditions after thermo-mechanical treatment of the analysed steels affects the change of their microstructure and mechanical properties. The obtained results allow assessing the impact of both the chemical composition and the applied thermo-mechanical treatment technology on the structural effects of strengthening of the newly developed steels.