Influence of catalytic graphitization on mechanical properties of carbonized biocarbon

The uniaxial compression strength and the deformation characteristics of beech-derived biocarbon, partially graphitized by the use of Ni-catalyst in the process of carbonization at different temperatures, have been measured using high-precision interferometry. It has been shown that the room temperature strength and the value of inelastic strain at the fracture point are very low for the carbonization temperature range of 1200-1500 °С. The curves of deformation consist of small jumps corresponding to displacements of 4-7 and 100-150 nm at the nanometer level, as well as to displacements of 1-3 µm at the micrometer level. The influence of the catalyst on the values of nanometer jumps and the number of micrometer ones have been observed. The results obtained are compared with previously published measurements of the elastic properties and the internal friction of this material and with the strength and strain characteristics of the beech-derived biocarbon carbonized without a catalyst.