粒度对Cu/FeNi复合材料性能的影响

EFFECT OF PARTICAL SIZE ON THE PROPERTIES OF Cu/FeNi COMPOSITE

采用粉末冶金方法，制备了低膨胀高导热Cu／FeNi复合材料，其中FeNi粉末粒度分别为300～150，150～100，100～74μm和小于74μm．研究了FeNi粒度对Cu／FeNi复合材料各种性能的影响．实验结果表明，随着FeNi粉末颗粒增大，材料的硬度、电阻率下降，而膨胀系数的变化规律则随Cu含量的不同而不同．扫描电镜能谱分析表明，FeNi颗粒和Cu颗粒中的Fe，Ni，Cu元素发生了互扩散，且随FeNi颗粒变小，互扩散量越大；而从金相照片又可知，FeNi颗粒较小时，易形成FeNi网络，FeNi颗粒较大时易形成Cu网络．本文分析认为，Cu／FeNi复合材料电导、硬度、热膨胀性能是由不同粒度情况下，材料形成Cu网络或FeNi网络和Fe，Ni，Cu互扩散的不同而共同决定的．

The Cu/FeNi composite with low thermal expansion and high thermal conductivity (high electrical conductivity) has been made by powder metallurgy, which is used as thermal support of semiconductor instead of W or Mo dish. By studying the composites with three different panical sizes of FeNi powders, 300-150, 150-100 and 100-74μm respectively, the effects of the partical size of FeNi powder on properties have been determined. It is found that the hardness and electrical resistivity decrease with the increase of FeNi panical size, while the thermal expansion with panical size varies with the composition of Cu. Through SEM analysis, it is suggested that there exists diffusion among elements Fe, Ni, Cu of FeNi and Cu powders. Through OM analysis, it is found that the smaller FeNi powder is, the easier it is to form FeNi net--structure while the larger FeNi powder is, the easier to form Cu net--structure. Perhaps the properties of this composite are determined by the diffusion between FeNi and Cu and the distribution of the two kinds of powders in this material.