METHOD OF OBTAINING CONSTRUCTIONAL ALUMINA CERAMICS Russian patent published in 2015 - IPC C04B35/111 C04B35/626 C01F7/42 

FIELD: chemistry.

SUBSTANCE: invention relates to the technology of constructional ceramic and can be applied for the production of wear-resistant products, applied as bearings, yarn-guide bars, guides for wire, ball valves in devices for pumping suspensions, as well as details of paper-making machines. To obtain ceramics jointly processed with a water solution of caustic soda are the alloy Al-Si (10-14 wt %) and the alloy Al-Mg (4-8 wt %), taken in the form of saw dust with the particle size of 0.05-0.5 mm with the ratio of the Al-Si alloy weight to the weight of the Al-Mg alloy from 0.5 to 1.5. The sediment is extracted from mother liquor and washed with water to the medium pH value of 8.5-9.5. The sediment is dried and subjected to thermal-processing in air at a temperature of 1350-1450°C for 30-60 minutes. A charge is prepared from the obtained cake, work-pieces are pressed under the pressure of 200-500 MPa and agglomerated in air at a temperature of 1500-1550°C for 10-30 minutes. The phase composition of ceramics is presented: α-Al₂O₃ (45-50 vol %), Al₂MgO₄ (30-40 vol %) and NaAlSiO₄ (15-20 vol %). Open porosity of the obtained material is 0.5-3%, density is 3.30-3.50 g/cm³, micro-solidity by Vickers is 32-47 GPa (at the load on the indentor of 1N), intensity of wear in conditions of dry friction by sliding constitutes 10^-5-5·10^-5 g/m.

EFFECT: increase of the wear-resistance, density and hardness of material.

6 cl, 1 tbl, 3 ex