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The article is focused on studying Fused Filament Fabrication (FFF) of alumina-filled polymer objects and their thermal properties. To track influence of inclusion type on thermal diffusivity of 3D printed samples with equiaxed and needle-like Al2O3 particles were made. The difference between the microstructure of needle and equiaxed compositions was evaluated using Phenom G2Pro (Phenom-World BV, Eindhoven, The Netherlands). The tests of thermal diffusivity were carried out on LFA 467 HT HyperFlash setup (NETZSCH Inc., Germany). It was found that the addition of 20 vol. % of ceramic particles in polyamide (PA12) increases its thermal conductivity, and the shape and location of inclusions play an important role in heat flow processes. It is shown that specimens with alumina needle-like inclusions demonstrated the highest values of thermal diffusivity. [ABSTRACT FROM AUTHOR]

In order to improve the efficiency of using powdered magnetic (including magnetite and maghemite) carbon sorbents in the technology of purifying water from heavy metals, dyes, organics and other pollutants, when one of the key stages of this technology is the prompt isolation of spent sorbent by magnetic separation, information is required about the magnetic susceptibility χ of particles of such sorbents. An approach to solving this problem has been formulated and implemented using a method tested for such problems. It is based on obtaining the experimental dependence of the magnetic susceptibility 〈χ〉 of the dispersed sample on the volume fraction γ in it of controlled particles and identifying the linear initial section of this dependence (when the particles are sufficiently disconnected and their magnetic interaction practically disappears). Then use of data from him allows to define χ as χ = 〈χ〉 /γ. For a magnetic carbon sorbent at magnetic field strength H = 61kA/m, a dependence on γ is obtained; using data 〈χ〉 from its linear section (at γ≤0.15-0.2) made it possible to establish that in this case γ = 0.095. It is offered to find the developed field dependence χ (in its characteristic area after extremum, up to H = 500 kA/m and more), in view of known for tasks of this sort the return power-law type of such dependence (with a power equals 0,7...0,8) [ABSTRACT FROM AUTHOR]