高纯致密Ti_2AlN陶瓷的合成及其高温行为

Synthesis of High-purity Dense Ti_2AlN Ceramic and Its High Temperature Performance

以Ti、Al和TiN粉按化学计量比配料,在原位热压(HP)烧结工艺条件下合成高纯致密Ti2AlN陶瓷材料。通过X射线衍射(XRD)分析烧结产物的相形成过程,用扫描电镜(SEM)和电子探针(EPMA)结合能谱仪(EDS)研究材料的显微结构特征。原位热压工艺合成Ti2AlN的最佳温度为1300℃,烧结试样的密度为4.22g/cm3,达到理论密度的97.9%,晶体发育完全,结构紧密,具有明显的层状结构。用高温显微镜研究了单相Ti2AlN的高温行为,1300～1500℃是坯体的烧结过程,1500～1580℃是Ti2AlN材料的软化温度,熔融温度高于1700℃。

High-purity Ti2A1N ceramic was prepared by in-situ hot pressing（HP） of Ti/A1/TiN powders in stoichiometric proportion. X-ray diffraction（XRD） was used to analyze the phase formation. Scanning electron microscopy（SEM） and electron probe micro-analysis（EPMA） coupled with energydispersive spectroscopy（EDS） were uti- lized to investigate the morphology characteristics. The density of Ti2 A1N prepared at the optimal synthetic temperature 1300C by HP was measured to be 4. 22g/cma , which reached 97.9% of its theory densities. Ti-AIN phase was well-developed with close and lametlated structure. The high temperature performance of Tie A1N was investigated by high temperature microscope. The sintering process was at the range of 1300-1500C. The softening temperature of Tiz AIN was at the range of 1500-1580C and its melting temperature was higher than 1700C.