In Situ Processing of Y-TZP/M-Type Hexaferrite Composite

Abstract

3Y-TZP/20 mass% La {Co_0.5Fe_0.5(Fe_0.9Al_0.1)₁₁}O₁₉ composites were successfully synthesized in situ during sintering from a mixture of 3mol% Y₂O₃-ZrO₂, La(Fe_0.9Al_0.1)O₃, Fe₂O₃, Al₂O₃ and CoO powders. Platelike La{Co_0.5Fe_0.5(Fe_0.9Al_0.1)₁₁}O₁₉ crystals were grown stably in a 3Y-TZP matrix over a temperature range of 1200 to 1325°C, which is wider than that of La(Fe, Al)₁₂O₁₉. Vickers hardness was 9.0GPa for the composite sintered from 1150 to 1325°C. 3Y-TZP/20 mass% La{Co_0.5Fe_0.5(Fe_0.9Al_0.1)₁₁}O₁₉ composite, which was sintered at 1325°C, exhibited a fracture strength of 630MPa. The composite which was sintered from 1200 to 1325°C exhibited a constant saturation magnetization of 7.2emu/g. The composite which was sintered at 1225°C exhibited a maximum coercivity of 3.8kOe.