Densification and microstructure evolution during SPS consolidation process in W-Ni-Fe system
Densification and microstructure evolution during SPS consolidation process in W-Ni-Fe system
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DOI：
10.1016/s1003-6326(11)60742-5
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发表时间：
2011-03-01
影响因子：
4.5
通讯作者：
Li Yuan-yuan
中科院分区：
文献类型：
--
作者：
Hu Ke;Li Xiao-qiang;Li Yuan-yuan
采用火花等离子烧结方法（SPS）对商品精细元素粉末中W-5.6Ni-1.4Fe（质量分数，%）混合粉末进行烧结，研究了不同升温速率下烧结过程中的致密化行为和微观组织演变。结果表明，SPS致密化过程可分为三个阶段。在初始不收缩阶段，快速加热使固态粉末颗粒瞬间放电，局部温度分布不均匀，增强了后期致密化；在中间固态烧结阶段，缓慢加热的SPS过程中扩散更充分；在最后的瞬态液相烧结阶段，钨晶粒迅速变圆和粗化，但快速加热有助于保持较小的晶粒尺寸。
Spark plasma sintering method (SPS) was used to consolidate mixed W-5.6Ni-1.4Fe (mass fraction, %) powders from commercial fine elemental powders, and both the densification behavior and microstructure evolution in sintering were investigated at different heating rates. The results show that the SPS densification process can be divided into three stages. At the initial unshrinking stage, fast heating generates instantaneous discharge and locally inhomogeneous temperature distribution in solid-state powder particles, enhancing later densification; during the intermediate solid state sintering stage, diffusion is more sufficient in the slow-heated SPS process; at the final transient liquid-phase sintering stage, tungsten grains become sphered and coarsen rapidly, but fast heating helps maintain rather small grain sizes.