CALCITE POWDER DEFORMATION IN THE PRESENCE OF AQUEOUS SOLUTIONS OF VARIOUS COMPOSITION

Измеренные скорости уплотнения порошка кальцита под действием одноосной нагрузки в присутствии насыщенного раствора CaCO, содержащего катионы магния или гумат-анионы, сопоставлены с расчетами скорости деформации, проведенными с учетом растворимости, кинетики растворения и скорости массопереноса вещества матрицы в поровой жидкости. Адекватность предложенной схемы расчета подтверждается незначительным различием экспериментальных и вычисленных значений (в пределах 20 %). Показано, что скорость деформации кальцита в растворах, содержащих ионы магния, лимитируется скоростью растворения материала из-за доломитизации поверхности. Замедление скорости уплотнения в присутствии гумат-анионов также происходит из-за частичного блокирования поверхности в результате адсорбции гумата. The rates of calcite powder compaction under uniaxial stress in CaCO saturated aqueous solutions containing magnesium cations or humate anions have been compared with computed rate estimations. The interplay of calcite solubility, dissolution kinetics, and mass transfer rate of solid matter through the liquid bulk controls the overall process kinetics. A not significant difference between the experimental and calculated datasets (within 20%) confirms the adequacy of the model proposed. The calcite creep rate in magnesium-containing media is limited by the material dissolution stage as a result of the surface dolomitization. The creep hindering by humate anions is likely to be due to the partial surface coverage with adsorbed matter.

Extrusion of Powder/Solid Clad Rods for a Desirable Hole Ratio in Powder Region

This paper focuses on the extrusion process of powder/solid clad rods with the desired hole ratio in the center to reduce the weight. The finite-element model about a lot of deformation body extrusion was successfully demonstrated. Raw steel powder and steel tube were consisted as powder/solid rods. While the obvious plastic deformation proceeding in deformation region, the hole ratio clearly lessened, then a little rose apart from the deformation region. The deformation parameters were determined for the purpose to lesson the weight of the rod to about 15% hole ratio in powder deformation region. The extrusion experiment and the tensile property test proved that the integrative property improved while the weight was reduced. The clad rod can be utilized in the solid suck rods.