MgAlON及MgAlON结合MgO材料烧结性能研究

Sintering of MgAlON and MgAlON-bonded MgO materials

以电熔镁砂细粉和颗粒、煅烧α-Al2O3微粉及金属铝粉为原料,在高纯氮气中烧成制备MgAlON及MgAlON结合MgO材料,并研究了化学反应引起的体积膨胀、氧化物挥发和保温温度(1450、1550、1650℃)对MgAlON及MgAlON结合MgO材料烧结的影响。结果表明:(1)在烧成过程中,形成过渡相MgAl2O4是引起MgAlON和MgAlON结合MgO试样体积膨胀的主要原因;(2)在低氧分压和高温条件下,MgAlON和MgAlON结合MgO试样的质量损失主要是由MgO挥发引起的;(3)对于MgAlON试样,高温(≥1550℃)烧成时显著的体积收缩使试样具有较高的密度和高强度;(4)对于MgAlON结合MgO试样,高温(≥1450℃)烧成时显著的体积膨胀和MgO大量挥发导致了试样的低密度和低强度。

MgAlON and MgAlON-bonded MgO materials were prepared in high purity nitrogen atmosphere with fused magnesite powder and grain,α-Al2O3 micropowder,and aluminum powder as starting materials.Influences of volume expansion caused by chemical reactions,oxides vaporization,and soaking temperatures（1 450,1 550,1 650 ℃） on sintering of MgAlON and MgAlON-bonded MgO materials were studied.The results show that：（1）in the process of firing,the formation of intermediate phase MgAl2O4 is the main reason of volume expansion in MgAlON and MgAlON-bonded MgO specimens;（2）in atmosphere with low partial oxygen pressure and high temperature,mass loss of MgAlON and MgAlON-bonded MgO specimens is mainly caused by MgO vaporization;（3）for MgAlON specimens,the remarkable volume contraction at high temperature（≥1 550 ℃） contributes to the relatively high bulk density and high strength;（4）for MgAlON-bonded MgO specimens,remarkable volume expansion and significant vaporization of MgO at high temperature（≥1 450 ℃） result in low bulk density and low strength.