摘要
通过设计加工具有3个模腔的石墨模具,并建立放电等离子烧结的有限元仿真模型,研究了烧结工艺对碳化硅块材物相及密度等的影响.结果表明,烧结时的电流主要通过石墨压头及样品产生热量实现样品的加热,且当模具温度高于1 200 K时,样品中心与模具的温度差异逐步增大,烧结模具的中心区域温度高于模具的温度.此外,采用放电等离子烧结同时制得了 3个碳化硅块体,实验结果表明,随烧结温度的增加,烧结助剂钇铝石榴石的含量逐渐减少,而碳化硅的含量及结晶性逐步增加,当烧结温度达到2 023 K时,得到了纯相的碳化硅.烧结所得的碳化硅密度为(3.103±0.043)g/cm3,致密度为97％.
Abstract
In this paper,the influence of sintering process on the phase and density of silicon carbide(SiC)bulk material is studied by designing and machining a graphite mold with three mold cavities.A fi-nite element simulation model of seark plasma sintering is also established.The results show that the cur-rent during sintering is mainly through the graphite indenter and the heat generated by the sample to heat the sample itself.When the temperature is higher than 1 200 K,the temperature difference between the sample center and the mold gradually increases.The temperature in the center region of the sintering mold is higher than the mold.Three SiC pellets are fabricated simultaneously by spark plasma sintering.The re-sults show that the sintering aid yttrium aluminum garnet content gradually decreases with the increase in temperature,while the SiC content and crystallinity increase gradually.When the sintering temperature reaches 2 023 K,pure SiC is obtained.The density of the sintered SiC is(3.103±0.043)g/cm3,with a denseness of 97％.
维普
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