碳对FeCr合金粉末的烧结机制和烧结颈长大行为的影响研究

Study on the Effect of Carbon on the Sintering Mechanism of FeCr Alloy Powder and the Behavior of Sintered Neck Growth

采用雾化Fe-15Cr粉末,在粉末中添加石墨,研究不同碳含量和烧结时间在烧结早期对粉末烧结颈生长速率的影响。实验结果表明,随着Fe-Cr粉末中碳含量的提升和烧结时间的延长,烧结颈的尺寸增大,长大速度加快,理论分析,烧结初期烧结颈的主导扩散机制为表面扩散;增加碳含量并没有改变其扩散机制,但是碳能降低铁基合金的熔点,是物质迁移更加容易,显著提高烧结颈的尺寸和表面扩散扩散系数。碳含量为0.07wt.%的扩散系数为0.91×10-^11;当碳含量增加到0.39wt.%时,扩散系数提高到2.90×10^-11。

The atomized Fe-15Cr powder were used to add graphite to the powder to study the effect of different carbon content and sintering time on the growth rate of the sintered neck of the powder at the early stage of sintering.The experimental results show that with the increase of carbon content in Fe-Cr powder and the prolongation of sintering time,the size of the sintered neck increases and the growth rate increases.Theoretical analysis shows that the dominant diffusion mechanism of the sintered neck at the initial stage of sintering is surface diffusion;The content does not change its diffusion mechanism,but carbon can lower the melting point of the iron-based alloy,which is easier to migrate.It significantly increase the size of the sintered neck and the surface diffusion coefficient.The diffusion coefficient of carbon content of 0.07 wt.%is 0.91×10^-11;when the carbon content is increased to 0.39 wt.%,the diffusion coefficient is increased to 2.90×10^-11.