纳米Ni-20Fe 颗粒增韧Al<sub>2</sub>O<sub>3</sub>复合材料的力学性能与磁性能

纳米Ni-20Fe 颗粒增韧Al₂O₃复合材料的力学性能与磁性能

摘要: 用机械化学及热压烧结方法成功制备了高致密Ni-20Fe/ Al₂O₃ 纳米复合材料。通过X2ray、FE-SEM、力学性能、磁性能测试, 结果表明, 复合后材料断裂韧性从纯α2Al₂O₃ 相的4. 7 MPa·m^1/2 提高到6. 2 MPa·m^1/2(19 % (Ni-20Fe) / Al₂O₃ ) , 断裂方式有沿晶断裂和穿晶断裂两种。当Ni-20Fe 合金的体积百分数达到19 %时, 复合材料的饱和磁化强度达33 emu/ g , 矫顽力为200 Oe , 且在低于500 ℃的情况下, 矫顽力基本不随温度而变, 具有良好的磁热稳定性。

Abstract: Ni-20Fe/ Al₂O₃ nanocomposites with high relative density (D ≥98 %) were fabricated using the mechanochemical method and the hot-pressing process. The fracture toughness is increased f rom 4. 7 to 6. 2 MPa·m^1/2 asNi-20Fe volume f raction increases f rom 0 to 19 %. Both the intergranular and the t ransgranular f ractures areobserved on the f racture surface by FE-SEM. When 19 % Ni-20Fe is added , the composite Ms is 33 emu/ g , H_c is200 Oe , and H_c keep s constant below 500 ℃, which shows good magnetic heat stability.