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采用反应热压烧结法制备MgAl2O4/Ti3SiC2复合材料,研究热压温度和MgAl2O4含量对该复合材料相组成、力学性能及抗氧化性能的影响。结果表明:热压温度影响MgAl2O4/Ti3SiC2复合材料相组成,在1 450℃烧结可得到性能良好的MgAl2O4/Ti3SiC2复合材料。引入适量的MgAl2O4,起到弥散强化的作用,有助于提高复合材料的力学性能,当引入量为20wt%时,抗弯强度为527.6 MPa,断裂韧性为7.09 MPa·m1/2。MgAl2O4/Ti3SiC2试样的抗氧化性能优于Ti3SiC2试样。MgAl2O4/Ti3SiC2复合材料在1 400℃氧化后的氧化层分两层,外层是Mg0.6Al0.8Ti1.6O5和金红石型TiO2,内层是由TiO2、方石英SiO2及少量未氧化的基体相混合组成。
The reaction of hot pressing sintering MgAl2O4 / Ti3SiC2 composite materials, hot pressing temperature and MgAl2O4 content of the composite phase composition, mechanical properties and oxidation resistance. The results show that the hot pressing temperature affects the phase composition of MgAl2O4 / Ti3SiC2 composites, and the MgAl2O4 / Ti3SiC2 composites with good properties can be obtained by sintering at 1 450 ℃. The introduction of the proper amount of MgAl2O4 can enhance the mechanical properties of the composites. When the loading is 20wt%, the flexural strength is 527.6 MPa and the fracture toughness is 7.09 MPa · m1 / 2. The oxidation resistance of MgAl2O4 / Ti3SiC2 sample is better than that of Ti3SiC2 sample. The oxide layer of MgAl2O4 / Ti3SiC2 composites after oxidation at 1400 ℃ is divided into two layers, the outer layer is Mg0.6Al0.8Ti1.6O5 and rutile TiO2, the inner layer is composed of TiO2, cristobalite and a small amount of unoxidized matrix composition.