放电等离子烧结中显微组织演变的自调节机制

A“Self-Adjusting”Mechanism of Powder Microstructure Evolution in Sps Process

目的 :探讨放电等离子烧结 (SparkPlasmaSintering ,SPS)这一目前国际上正在兴起的粉末烧结新技术的内在机制。方法 :选用纯金属铜粉作为烧结原料 ,在分析烧结曲线的基础上设计一系列烧结实验 ,研究不同烧结阶段的显微组织、烧结体晶粒尺寸分布、致密度及上述参量的演变特征。结果 :根据对烧结体显微组织的观察和定量分析 ,提出了SPS过程中显微组织演变的“自调节机制” ,并发展了烧结体致密度变化的分析模型。结论 :显微组织演变的“自调节机制”揭示了制备高致密度、均匀、细晶材料的SPS技术优势的内在机制 ;

Objective:To study the sintering mechanism of Spark Plasma Sintering (SPS), which is a newly developed sintering technology attracting more and more interests in the world. Method: Using pure Cu powder as the sintering sample, based on the analysis of the sintering curves, a series of experiments were designed. The microstructures, grain size distribution, relative density, as well as the evolution of the above parameters during SPS, have been studied. Results: A ”self-adjusting” mechanism of powder microstructure evolution in the process of SPS has been proposed, and a simple model to predict the variations of the relative density during SPS has also been developed. Conclusion: The ”self-adjusting” mechanism of microstructure evolution during SPS is essential to the advantages of high consolidation, homogeneity and preparation of fine microstructures of SPS. The analytical model can be used to predict the consolidation process of SPS under various processing parameters.