【摘要】 热压烧结n(TiC)∶n(Ti)∶n(Si)∶n(Al)=2∶1∶1∶0.2的混合粉末制备了含铝Ti3SiC2材料并研究了它的力学性能、电性能、热性能和高温氧化性能。该试样的抗压强度、弯曲强度、断裂韧性和维氏硬度分别为854MPa、420MPa、5.8MPa·m1/2和3.5～5.0GPa;25℃和800℃时的电导率分别为4.3×106S/m和1.0×106S/m;热膨胀系数为9.0×10-6/K。固溶在基体中的Al改变了材料的氧化机理,氧化过程中Al的向外扩散代替了Ti的向外扩散,并在表面形成致密以αAl2O3为主要成分的氧化膜,提高了材料的抗氧化性能。更多还原

【Abstract】 The mechanical properties, thermal properties, electrical properties and oxidation behavior at high temperature of Ti₃SiC₂ with solute Al synthesized by hot pressing the mixture powder with the molar ratio 2TiC/Ti/Si/0.2Al were studied in this paper. The compressive strength, flexural strength, fracture toughness and Vicker’s hardness were 854 MPa, 420 MPa, 5.8 MPa·m¹/2 and 3.5～5.0 GPa; at 25 ℃ and 800 ℃, the electrical conductivities were 4.3×106 S/m and 1.0×106 S/m, respectively. The thermal expound coefficient was 9.0×10^-6 /K. The solute Al altered the oxidation mechanism of Ti₃SiC₂. The oxide layers consisted of a mass of α-Al₂O₃ formed by the outward diffusion of Al, instead of the outward diffusion of Ti, were observed on oxidized samples as a dense and adhesive protect scale. The oxidation mechanism varied with the additive aluminum, which greatly improved the oxidation resistance of Ti₃SiC₂.更多还原