国产乱子伦精品无码吗专区-国产桃色五月综合精品一区二区-久久久久中文字幕2021精品-日韩久热蜜桃视频中文字幕

熱線:021-50550642
TECHNICAL ARTICLES

技術(shù)文章

當(dāng)前位置:首頁技術(shù)文章不同操作條件下氧化鋁燒結(jié)對致密化的影響

不同操作條件下氧化鋁燒結(jié)對致密化的影響

更新時(shí)間:2016-07-15點(diǎn)擊次數(shù):3066

Nearly pure -alumina samples produced by uniaxial pressing were flash sintered under electrical fieldsranging from 500 V/cm to 1500 V/cm in experiments at constant heating rate. Sintering temperature sig-nificantly decreased with the applied E-field even down to ≈900?C at 1500 V/cm. The onset temperaturefor flash sintering can be successfully modelled as a function of the applied voltage. The sintering temper-ature is also shown to be strongly affected by the electrode materials used during the treatment: usingsilver or carbon electrodes the sintering temperature is about 300?C lower than when using platinumelectrodes. In addition, the bulk density and porosity of the sintered alumina ceramic correlate stronglywith the imposed current limit. Power dissipation was analysed before and during flash sintering; theactivation energy for conduction was calculated in both cases, indicating that the process is based onionic diffusion phenomena. Finally, we showed that during flash sintering the activation energy for con-duction decreases, suggesting the occurrence of physical or structural modifications induced by currentlocalization at the grain boundaries.