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针对利用Ti-B4C-C体系复合粉制备Ti(C,N)-TiB2陶瓷坯件时,复合粉中金属组元易被氧化,使喷射沉积坯件内含有有害相TiO2的问题,利用综合热分析仪研究分析了该复合粉中金属组元Ti的氧化规律,探讨了向喷射体系中加入5wt%Al对复合粉氧化规律及喷射沉积坯件组织结构的影响。结果表明:在自反应喷射成形过程中,喷射体系中金属组元Ti的氧化机理遵从抛物线-线性氧化规律;复合粉体系中引入活性组元Al后,由于Al的选择氧化,在金属表面形成具有保护性作用的致密氧化膜Al2O3,有效抑制了Ti的氧化;金属的氧化机理转变为Ti-Al二元金属的线性-抛物线规律;喷射沉积坯件的致密度、硬度、弯曲强度和断裂韧性等性能也由97.2%、17.3 GPa、387 MPa、6.0 MPa.m1/2分别提高到97.7%、20.6 GPa、425 MPa、7.3 MPa.m1/2。
For the Ti (C, N) -TiB2 ceramic blank prepared by the Ti-B4C-C composite powder, the metal components in the composite powder are easily oxidized and the harmful phase TiO2 is contained in the sprayed blank. The analyzer analyzed and analyzed the oxidation regularity of the metal component Ti in the composite powder and discussed the effect of adding 5wt% Al to the composite powder on the oxidation of the composite powder and the microstructure of the spray deposition blank. The results show that the oxidation mechanism of Ti in the injection system follows the parabolic-linear oxidation rule. In the composite powder system, after the active component Al is introduced, the selective oxidation of Al is formed on the surface of the metal. The protective oxide film of Al2O3 effectively inhibits the oxidation of Ti. The oxidation mechanism of metal changes to the linear-parabolic law of Ti-Al binary metal. The density, hardness, flexural strength and fracture toughness The performance also increased from 97.2%, 17.3 GPa, 387 MPa and 6.0 MPa.m1 / 2 to 97.7%, 20.6 GPa, 425 MPa and 7.3 MPa.m1 / 2, respectively.