Microwave sintering of Yb:YAG transparent laser ceramics
Microwave sintering of Yb:YAG transparent laser ceramics
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DOI：
10.1016/j.optmat.2012.07.014
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发表时间：
2013-02
影响因子：
3.9
通讯作者：
L. Esposito;A. Piancastelli;Y. Bykov;S. V. Egorov;A. Eremeev
中科院分区：
文献类型：
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作者：
L. Esposito;A. Piancastelli;Y. Bykov;S. V. Egorov;A. Eremeev
为了保证气孔的消除和无污染，通常在无石墨炉中的高真空条件下进行反应烧结。另一种致密化技术是场辅助工艺，如放电等离子烧结和微波烧结。这两种方法都具有升温速度快、烧结温度低、烧结时间短的特点。微波烧结过程不同于电阻加热，因为热能在粉末压坯中通过电磁辐射吸收而产生，并在其体内产生均匀的温度分布。激光陶瓷的微波烧结的有利区别在于没有任何具有高温的元素，如电加热器或模具，这些材料会污染烧结的部件。此外，在体积微波加热下，体内存在的逆温度分布有利于气孔率的消除。对Yb：YAG样品进行了微波烧结实验，给出了实验结果。样品在回旋管系统上烧结，工作频率为24 GHz，微波功率高达6kW。在不同的温度-时间条件下对掺入1.0、5.0和9.8at.%Yb2O3的Yb2O3进行了反应烧结。将所得样品的显微组织和光学透过率与常规高真空烧结样品进行了比较。
Reactive sintering of YAG based ceramics is generally performed under high vacuum in graphite-free furnaces in order to guarantee the elimination of pores and absence of any contamination. An alternative densification technique is the field assisted process such as spark plasma sintering and microwave sintering. Both of these methods are characterized by very fast heating rates, low sintering temperatures and short sintering times. The microwave sintering process is different from electric resistance heating since heat is generated in the bulk of the powder compact through electromagnetic radiation absorption and creates within its body uniform temperature distribution. Microwave sintering of laser ceramics is advantageously distinguished by the absence of any elements having high temperature such as electric heaters or dies which materials can contaminate the sintered parts. In addition, the inverse temperature distribution that exists within the body under volumetric microwave heating is favorable for elimination of porosity. Microwave sintering of Yb:YAG samples were tested and the obtained results are presented. The samples were sintered on a gyrotron-based system operating at a frequency of 24GHz with microwave power up to 6kW. Reactive sintering of YAG doped with 1.0, 5.0, and 9.8at.% Yb2O3was performed in different temperature–time regimes. The microstructure and the optical transmittance of the obtained samples were compared to those of samples obtained by conventional high vacuum sintering.