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    烧结助剂TiO2添加量及烧结制度对Cr2O3烧结致密化行为的影响

    Effect of TiO2 Sintering Assistant Addition and Sintering System on Sintering Densification Behavior of Chromium Oxide

    • 摘要: 以Cr2O3微粉为原料、TiO2微粉为烧结助剂,在不同温度(1 000~1 500 ℃)、不同保护气体(氩气、氮气)中烧结制备Cr2O3,研究了TiO2添加量(0,1%,3%,5%,质量分数)、烧结温度和烧结气氛对Cr2O3烧结致密化行为的影响。结果表明:随着TiO2添加量增加,试样线收缩率和相对密度增加,致密化程度提高,当TiO2添加量为5%时,线收缩率和相对密度最大,分别为16.25%,92.51%,添加TiO2后形成的(Cr0.88Ti0.122O3置换固溶体可以提升扩散传质速率,从而促进烧结致密;随着烧结温度升高,Cr2O3的烧结致密化程度先升高后降低,1 300 °C下烧结最致密,氮气中烧结后在Cr2O3颗粒表面形成Cr2N膜层,可以发挥类似液相作用,提高烧结速率,制备的Cr2O3相比在氩气中更致密。

       

      Abstract: Cr2O3 material was prepared under different temperatures (1 000–1 500 °C) and different protective atmospheres (argon, nitrogen) by using Cr2O3 powder as raw material and TiO2 powder as sintering assistant. The effect of TiO2 addition (0, 1%, 3%, 5%, 5%, mass fraction), sintering temperature and sintering atmosphere on sintering densification behavior of Cr2O3  was analyzed. The results show that with the increase of TiO2 addition, the linear shrinkage rate and relative density of the sample increased, and the densification degree increased. When the TiO2 addition was 5%, the linear shrinkage rate and relative density reached the maximum, which were 16.25% and 92.51%, respectively. After adding TiO2, (Cr0.88Ti0.12)2O3 replacement solid solution was formed to improve the diffusion mass transfer rate and promote sintering densification. With the increase of sintering temperature, the sintering densification degree of Cr2O3 first increased and then decreased, and reached the maximum at 1 300 °C. After sintering in nitrogen atmosphere, the Cr2N film was formed on the surface of Cr2O3 particles after sintering in nitrogen, which could play a similar role to the liquid phase and improve the sintering speed, the Cr2O3 prepared was denser than that prepared in argon atmosphere.

       

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