METHOD OF OBTAINING CONSTRUCTIVE ALUMINIUM OXIDE CERAMICS Russian patent published in 2014 - IPC C04B35/111 C04B35/626 C01F7/42 

FIELD: chemistry.

SUBSTANCE: invention relates to a technology of densely sintered ceramic materials of constructive purpose. In order to manufacture a ceramic material an initial alloy of aluminium with magnesium and silicon (8-12 wt %) is processed with a water solution of sodium hydroxide with constant mixing and a temperature of 80-95°C. The sediment is washed to pH=8-8.7, dried and thermally processed in air at a temperature of 1100-1250°C for 100-150 minutes. The obtained product is used to prepare a charge for pressing raw workpieces. Sintering of the pressed under 150-200 MPa workpieces is carried out in air by heating at a rate of 300-400°C/h to a temperature of 1580-1610°C, then to a temperature of 1610-1650°C at a rate of 80-100°C/h with further isothermal exposure for 60-120 minutes. A phase composition of ceramics is represented by α-Al₂O₃ (70-79 vol %), NaAlSiO₄ (6-12 vol %) and Al₂MgO₄ (5-15 vol %); general porosity is 1%, bending strength is 250-300 MPa, impact bending strength is 5·10³-5.9·10³ J/m².

EFFECT: manufacturing products, combining high strength parameters with increased thermomechanical properties and elements of the impact-resistant protection.

3 cl, 3 ex, 1 tbl