Densification and microstructure evolution during SPS consolidation process in W-Ni-Fe system  

W-Ni-Fe合金的放电等离子烧结致密化与微观组织演变(英文)

作　　者：胡可[1] 李小强[1] 杨超[1] 李元元[1] 

机构地区：[1]华南理工大学国家金属材料近净成形工程研究中心,广州510640

出　　处：《Transactions of Nonferrous Metals Society of China》2011年第3期493-501,共9页中国有色金属学报（英文版）

基　　金：Project (2010CB635104) supported by the National Basic Research Program of China;Project (2007AA03Z112) supported by the National High-Tech Research and Development Program of China;Project (9140A18040709JW1601) supported by the Advanced Research Fund of DOD, China;Project (2009ZZ0019) supported by the Fundamental Research Funds for the Central Universities, China;Project (NCET-10-0364) supported by the Program for New Century Excellent Talents in University, China

摘　　要：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.采用放电等离子烧结(SPS)技术固结成形W-5.6Ni-1.4Fe(质量分数,%)混合粉末,研究不同加热速率对烧结致密化行为和微观组织演变规律的影响。结果表明,W-5.6Ni-1.4Fe合金的SPS致密化过程可以划分为三个阶段。初始不收缩阶段,快速加热导致粉末颗粒接触区产生瞬间放电,并在颗粒表面产生局部高温,强化后续烧结致密化;致密化过程主要发生在中期固相烧结阶段,缓慢加热有助于扩散更加充分;在后期瞬时液相烧结阶段,钨晶粒球化并迅速长大,且快速加热可获得更为细小的晶粒。

关 键 词：densification behavior microstructure evolution SPS W-Ni-Fe alloy 

分 类 号：TF124.5[冶金工程—粉末冶金]