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烧结温度对Cu-C-SnO2多孔材料组织与性能的影响

Effects of sintering temperature on microstructures and properties of Cu-C-SnO2 porous materials

  • 摘要: 采用SiO2-B2O3-Al2O3助焊剂辅助常压烧结法制备了铜-石墨-氧化锡(Cu-C-SnO2)复合多孔材料,对其显微组织和物理性能进行了测试,研究了烧结温度对Cu-C-SnO2多孔材料组织和性能的影响。结果表明,复合多孔材料主要由金属Cu、石墨和氧化物陶瓷相构成;随着烧结温度升高,SnO2逐渐减少,莫来石等矿化陶瓷相逐渐增多;当烧结温度从750℃升高到800℃时,Cu2O增多,当烧结温度高于800℃时,Cu2O随烧结温度的升高而减少;当烧结温度为950℃时,Cu相发生显著再结晶而晶粒粗大;材料的电阻率、渗油率和空气粘性渗透系数随烧结温度的变化呈现出相似的变化规律,都随烧结温度的增加而先减小后增大,在烧结温度850~900℃范围内达到最小值;烧结线收缩率和材料密度随烧结温度的变化呈现出相似的变化规律,都是随烧结温度的升高而增大,在烧结温度800℃附近存在一个临界值,在该临界值两侧,烧结线收缩率和材料密度随烧结温度变化的速率明显不同;在烧结温度800~850℃之间,材料里氏硬度存在一个突变点,在该突变点两侧,材料里氏硬度都随烧结温度的升高而升高。

     

    Abstract: The Cu-C-SnO2 composite porous materials were prepared by pressureless sintering with the addition of SiO2-B2O3-Al2O3 scaling powders. The effects of sintering temperature on the microstructures and properties of the Cu-C-SnO2 porous composites were investigated. The results show that, the porous composites are composed of metal Cu, graphite, and oxide ceramic phases. As the sintering temperature increases, the content of SnO2 decreases and the content of oxide ceramic phases (such as mullite) increases. The content of Cu2O increases when the sintering temperature rises from 750 ℃ to 800 ℃, which decreases as the sintering temperature above 800 ℃. At the sintering temperature of 950 ℃, the Cu grains coarsen observably because of the recrystallization. The electric resistivity, oil penetration rate, and air permeability coefficient of the composites vary similarly with the change of the sintering temperature, and there are the minimum values in the sintering temperature range of 850 ℃ to 900 ℃. The sintering shrinkage and density of the sintered compact vary similarly with the change of the sintering temperature, and there are the critical values at the sintering temperature near 800 ℃. The change rates of the sintering shrinkage and density of the sintered compact are significantly different on the both sides of the critical values. The hardness of the sintered compact increases with the rising of sintering temperature and shows a jump in the range of 800 ℃ to 850 ℃.

     

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