Effect of mechanical processing on thermal and mechanical properties of fibrous fumed alumina compacts

In the present study, the fibrous fumed alumina compact with low thermal conductivity is prepared with a mechanical processing technique. The thermal conductivity of the compact remains low up to a temperature of 350°C. For the fibrous compact, the mechanical processing parameters play important role on controlling the thermal insulation capability. The thermal conductivity of compact increases from 0.036 to 0.042 W/m∙K by increasing the rotating speed of rotor. On the other hand, the value remains low by increasing processing time. The strength is decreased due to the increase of processing time. Thus, a lower rotating speed and a shorter processing time could result in a compact with favorable thermal insulation and strength. The results can be related to the surface structure of the coated alumina fibers and granulated structure within the compacts.