放电等离子烧结过程中粉末颗粒内部温度场的模拟及颈部演变

TEMPERATURE DISTRIBUTION SIMULATION AND NECK EVOLUTION OF POWDER PARTICLES DURING SPARK PLASMA SINTERING

建立了用于模拟导电材料在放电等离子烧结(SPS)过程中粉末颗粒热传导行为的计算模型．以球形铜粉为研究对象, 对颗粒内部温度分布和颈部尺寸变化进行了模拟计算和分析,模拟结果表明:SPS过程中颗粒内部的温度分布极不均匀,烧结颈部的长大速率在烧结过程中并不一致．不同烧结阶段颈部尺寸变化的模拟结果和实验测定结果基本吻合．揭示了SPS过程中烧结颈部形成和长大的根本原因是颗粒接触部位的局部高温．

A model has been developed to simulate the heat transfer behavior during spark plasma sintering （SPS） process and by using the pure spherical copper particles as an example, the temperature distribution and the neck size evolution of the powder particles have been studied. There is a greatly inhomogeneous distribution of the temperature in the particle, and the growth rates of the necks are different. The obtained simulation results show a good agreement with the experimental measurements. By the modeling and experimental studies, the intrinsic mechanisms of neck formation and neck growth are well explained.