三元层状氮化物Ti_4AlN_3材料的合成及微观结构研究

Research on the Synthesis and Microstructure of Layered-ternary Nitride Ti_4AlN_3

以Ti、Al、TiN粉为原料,采用热压烧结工艺在1400℃合成了含少量TiN和Al3Ti的Ti4AlN3块体材料,分别研究了不同原料配比、烧结温度及合成时间下烧结试样的相组成。混合粉Ti/1.2Al/3TiN在1400℃下保温2h所得烧结试样经背散射电子像结合EDS能谱分析,证实成功合成了Ti4AlN3材料。烧结试样晶粒尺寸为5～10μm,晶体呈层状或板状结构,结晶良好,结构致密。相对密度达到99.3%,维氏硬度及电导率分别为3.9～5.1GPa和1.2×106Ω-1.m-1,表明其具有优良的机械加工及导电性能。

Predominantly single-phase bulk samples of Ti4AlN3 with a few amounts of TiN and Al3Ti was successfully synthesized by a hot-pressing method using Ti,Al and TiN powders as starting materials. The phase composition of the sintered samples with different starting composition,sintering temperature and holding time were presented. The results of BEI and EDS show that Ti4AlN3 is synthesized with the initial composition of Ti/1.2Al/3TiN at 1400 ℃ for 2 h.The sintered sample is fully dense and well-developed in laminate shape with dimension of 5-10 μm. The relative density of it reachs to 99.3%. Besides,the Vickers hardness and electrical conductivity are 3.4-4.5 GPa and 1.2×106 Ω-1·m-1,which performs well on machinability and electrical property.