论文部分内容阅读
以Ti、Al、TiO2为起始原料,以Er2O3为掺杂剂,原位热压合成了Er掺杂Al2O3/TiAl复合材料。通过XRD、SEM分析及力学性能测试,研究了不同Er2O3引入量对合成Al2O3/TiAl复合材料微观结构和力学性能的影响。结果表明:复合材料主要由TiAl、Ti3 Al、Al2 O3相和少量Al10 Er6 O24相组成,含Er相主要分布在基体相晶界处;掺杂0.01 mol Er2 O3制得的复合材料,经1250℃保温2 h真空热压烧结后表观断裂韧性达到最大值(10.41 MPa.m1/2),经1300℃保温2 h真空热压烧结后弯曲强度达到最大值(456.06 MPa);当Er2O3掺杂量增加到0.02 mol时,复合材料的弯曲强度和表观断裂韧性均呈减小趋势。微观结构分析表明,掺杂0.01 mol Er2O3的复合材料断口毛糙,颗粒尺寸变小,增强相分布较均匀,表明适量的Er2O3掺杂可细化复合材料晶粒尺寸,提高增强颗粒分布均匀度,起到增强增韧的效果。
Er-doped Al2O3 / TiAl composites were synthesized by in-situ hot pressing using Ti, Al and TiO2 as starting materials and Er2O3 as dopant. The effects of different amounts of Er2O3 on the microstructure and mechanical properties of the synthesized Al2O3 / TiAl composites were investigated by XRD, SEM and mechanical properties tests. The results show that the composites consist mainly of TiAl, Ti3Al and Al2O3 phases and a small amount of Al10Er6O24 phases, and the Er-containing phases are mainly distributed at the grain boundaries of the matrix. The composites doped with 0.01mol Er2O3 are annealed at 1250 ℃ The apparent fracture toughness reached the maximum (10.41 MPa.m1 / 2) after vacuum hot pressing sintering for 2 h, and reached the maximum (456.06 MPa) after vacuum hot-pressing sintering at 1300 ℃ for 2 h. When Er2O3 doping amount Increasing to 0.02 mol, the flexural strength and apparent fracture toughness of the composites showed a decreasing trend. The microstructure analysis showed that the fracture surface of the composites doped with 0.01 mol Er2O3 becomes coarse, the particle size becomes smaller and the distribution of reinforcing phase is more uniform. It shows that the proper amount of Er2O3 doping can refine the grain size of the composite and improve the uniformity of the particle distribution. To enhance the effect of toughening.