Low-Temperature Synthesis and Micro-Morphology Observation of Transparent MgAl_2O_4 Nano-Ceramics

摘要

Transparent MgAl_2O_4 nano-ceramics were prepared by ultrahigh-pressure-sintering method, using improved nano-sized powder synthesized by high-temperature calcination. The synthesis temperatures were exactly measured by nichrome-NiSi thermocouple passing through the samples. The micro-morphology of the ceramics was observed by means of dynamic force microscopy (DFM), and the relation between transparency and micro-morphology was investigated. The results show that, the sintering temperatures, now calibrated, of transparent nano-ceramics are just 540～700°C, which are much lower than those of conventional nano-ceramics and transparent ceramics, and the uniformity of grain sizes and orderliness of the grain array are beneficial to the transparency and integrity of the ceramics.