With composite powders of Ti-B4C-C and Ti-B4C-C-Al systems as reactants, Ti(C, N)-TiB2 -based composite ceramic preforms were prepared by self-reactive spray forming technology. XRD, SEM, EDS and TEM were used to investigate the influence of 5wt% Al addition on the structure and properties of the preforms. It was shown that the performs made from Ti-B4C-C system were mainly composed of TiC0.3N0.7 and TiB2, with by-product phase of TiO2. Relative density, Vickers hardness, flexural strength and fracture toughness of Ti-B4C-C preforms were 97.2%, 17.3GPa, 387MPaand 6.0MPam1/2, respectively. By adding 5wt%Al in the sprayed system, the by-product of the preforms was the desirable phases of AI2O3 and Ti3Al, not TiC>2, though the main phases of Ti-B4C-C-Al preforms remained to be TiC0.3N0.7 and TiB2. The length to diameter ratio of the TiB2 grains increased obviously. As a result, relative density, Vickers hardness, flexural strength and fracture toughness of Ti-B4C-C-Al preforms ascended to be 97.7%, 20.6GPa, 425MPa and 7.3MPam1/2, respectively. The additive Al effectively restrained the oxidation of Ti in the spray forming process, which improved the mechanical properties of the preforms greatly.%分别以Ti-B4C-C体系和Ti-B4C-C-Al体系复合粉为反应原料,利用自反应喷射成形技术制备Ti(C,N)-TiB2基复合陶瓷坯件.利用XRD、SEM、EDS、TEM等方法,研究分析了向喷射体系中加入5wt%金属Al对喷射沉积坯件组织结构、主要力学性能的影响及其原因.结果表明,Ti-B4C-C体系的喷射沉积坯件主要由TiC0.3N0.7和TiB2主相及TiO2副产物相组成,其致密度、维氏硬度、弯曲强度、断裂韧性等性能分别为97.2%、17.3GPa、387MPa、6.0MPa·m1/2;喷射体系中添加5wt%金属Al后,喷射沉积坯件的主相仍为TiC0.3N0.7和TiB2,但副产物相中不含有害相TiO2,而增加了对复合材料有益的Al2O3与Ti3Al相,坯件内TiB2颗粒长径比增大,出现大量长棒状晶,并使坯件的致密度、维氏硬度、弯曲强度、断裂韧性等性能也分别提高到97.7%、20.6GPa、425MPa、7.3MPa·m1/2.可见金属Al的添加可有效抑制喷射过程中Ti的氧化,明显改善喷射沉积坯件的综合力学性能.
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