Fe3O4颗粒对硼酸铝晶须增强铝复合材料热膨胀行为的影响

硼酸铝晶须增强铝复合材料中加入Fe3O4颗粒可以降低该复合材料的热膨胀系数．研究认为复合材料中Fe3O4颗粒在制备过程中部分被氧化，在热膨胀测试过程中被氧化的Fe3O4又被还原，其体积将变小，基体铝的膨胀受到限制，相当于具有负膨胀系数性质，从而起到了降低复合材料热膨胀系数的作用．结合复合材料中Fe3O4磁场热重曲线分析，阐述了颗粒的残余应力在热循环中的变化情况．

Effect of Fe3O4 Particles on Thermal Expansion Behavior of Al 18B4O33 Whisker Reinforced Aluminum Composite

It is shown that the addition of Fe_3O_4 particles can decrease the coefficient of thermal expansion(CTE)of aluminum borate whisker reinforced aluminum composite.The reason is that the Fe_3O_4 particles were partially oxidized during fabrication,the oxidized Fe_3O_4 particles were reduced during the thermal expansion measurement,resulting in decreasing of the volume of Fe_3O_4 particles, which restricted the expansion of matrix aluminum and could be considered as a negative CTE rein- forcement to reduce the CTE of the composite.On the basis of the measured thermogravimetric curve analysis of Fe_3O_4 particles in the composite,the change of residual stress of Fe_3O_4 particles during heat-cycling was also analyzed.